My monthly Food Matters Q and A column in the San Francisco Chronicle appears this weekend:

Are 8 glasses of water a day really necessary?

Q: It’s such a hot summer and I’m sweating all the time, but I don’t feel thirsty. Do I have to force myself to drink eight glasses of water a day?

A: San Franciscans: Please, no complaints about summer fog. Where I live, it’s hot and humid, and staying hydrated takes work.

Everybody needs water to replace the amounts lost through breath, sweating and excretions. In comfortable temperatures, the amounts lost conveniently come out to about a quart of water for every thousand calories consumed. If you eat 2,000 calories a day, you need about 2 quarts of water.

But water equivalents – juice, coffee, tea, soda and anything else with water in it, including food – work just as well. Watermelon is called watermelon for a reason. It is mostly water and perfect for hot summer days.

Mostly, you don’t have to keep track of how much liquid you drink. Thirst takes care of it. If you need water, you feel thirsty and you get something to eat or drink. Problem solved.

But thirst doesn’t work very well at times when it is most needed – in very hot weather, at high altitudes or during heavy exercise. People in hot climates, mountain climbers and athletes have to force themselves to drink.

How can you tell when you need water? This is easy. Look at your urine. If you are dehydrated, your urine is bright yellow and smelly. If you are getting enough water, your urine is pale and practically odorless.

Except for these exceptions, hardly anyone needs to worry about how much water to drink. That “hardly anyone,” however, also includes children and the elderly, who tend not to regulate water balance very well. Beyond these exceptions – as you shivering San Franciscans can attest – thirst works well as a guide to how much to drink.

Q: A young woman I know got a nasty combination of altitude sickness and electrolyte imbalance when she was hiking in the Sierra Nevada. She sipped water constantly, ended up drinking too much, and got so sick from lack of salt that she had to be airlifted out. Are those Gatorade-like drinks that replenish electrolytes any better than plain water when you are hiking or exercising hard?

A: Those drinks might help, but your friend also must not have been eating much on that hike. Foods are excellent sources of electrolytes.

Electrolytes are minerals like sodium, potassium and chloride that help balance blood acidity. They are lost in sweat, which is why sweat tastes salty. Our bodies have plenty of electrolytes. Salt, for example, is usually eaten in great excess. Normal sweat losses don’t matter much, unless we are vigorously exercising or sweating profusely.

But sweating is easy to miss at high altitudes because it evaporates so quickly. The higher the altitude, the easier it is to overlook fluid and electrolyte losses.

High altitude also disrupts normal appetite, so climbers don’t feel hungry or thirsty. Elite climbers know to pack lightweight foods and supplements made especially for that purpose, and to force themselves to eat and drink frequently.

Drinks advertised as electrolyte supplements do indeed contain electrolytes. Gatorade Orange Sports Drink, for example, contains water as the first ingredient, followed by sugars (sucrose syrup, high-fructose corn syrup), flavors and three sources of electrolytes – salt (sodium chloride), sodium citrate and monopotassium phosphate – along with color additives and thickeners.

If you are an athlete working out for an hour or more, Gatorade might replenish your sodium, potassium and chloride more quickly than food can, but not by much. An 8-ounce Gatorade serving provides just 1 percent of the daily value for potassium (30 milligrams) and 5 percent of the daily value for sodium (110 milligrams).

Gatorade is a sweetened drink supplemented with a few salts, but with less sugar and fewer calories than a regular soft drink. On the basis of electrolytes, PepsiCo, its parent company, markets Gatorade as a better choice than any other drink, including water. Nothing, says PepsiCo, rehydrates, replenishes and refuels athletes better. According to Advertising Age, the company backs up that contention with a hefty advertising budget – $118 million in 2009.

Studies do show that replenishing electrolytes is a good thing to do at high altitude or during any other extreme activity. But hikers can do this with food or supplements without having to carry additive-laden sugary drinks in a backpack.

An average carrot, for example, provides 230 milligrams of potassium and 50 milligrams of sodium. Many other vegetables have similar electrolyte profiles. Nobody wants to carry heavy foods up a mountain, which is why sports shops sell dehydrated foods and special supplements for high-altitude climbers.

It’s a good idea to drink water at high altitude, but also to eat plenty of good food at regular intervals.

Marion Nestle is the author of “Food Politics,” “Safe Food,” “What to Eat” and “Pet Food Politics,” and is a professor in the nutrition, food studies and public health department at New York University. E-mail her at food@sfchronicle.com, and read her previous columns at sfgate.com/food.

http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2010/07/30/FDD51EK7K0.DTL

This article appeared on page K – 5 of the San Francisco Chronicle

My monthly Food Matters column in the San Francisco Chronicle answers readers’ questions and these tend to be about nutrition rather than food politics.   Today’s column is about diets aimed at controlling the amount of acid excreted in urine:

Low acid diet may not prevent bone loss

Q: I’ve just read “Building Bone Vitality: A Revolutionary Plan to Prevent Bone Loss and Reverse Osteoporosis,” by Amy Lanou and Michael Castleman.

The writers contend that a high acid diet causes bone loss and other negative health outcomes. The book is so well documented and the theory so logically explained that I find it compelling.

However, I am not a scientist and would appreciate your opinion.

A: Ordinarily I would not bother to read a book with the word “Revolutionary” in its title. In diet books, “revolutionary” invariably means using a grain of scientific truth to construct a dietary theory that contradicts current thinking but cannot be proven by current research.

But two readers asked about this book and I was curious about it for another reason. Last year, I gave a talk at a spa where I was seated at dinner next to a couple who announced that they were following a low-acid diet. To my amazement, they excused themselves during the meal to measure the pH of their urine.

Stay with me: pH is a measure of acidity or hydrogen ion concentration. pH 7 is neutral. Above 7 is basic or alkaline. Below 7 is acidic.

I could not believe that anyone would bother to measure urine pH, let alone leave dinner to do so. The pH of blood is tightly regulated and must stay within a slightly alkaline range of 7.36 to 7.4. Bicarbonate buffering systems keep it that way, and excreting excess acid is exactly what the kidney is supposed to do.

The authors are proponents of vegan diets. Here, they argue that small increases in blood acidity cause calcium to be leached from bones to help neutralize it. Over time, these small losses weaken bones and lead to osteoporosis.

Adding calcium to the diet, they claim, is not enough to replace the losses. They parse the results of 1,200 research studies to argue that dairy foods cannot protect against osteoporosis. Instead, low acidity – meaning too much meat – provides the best current explanation for worldwide rates of osteoporosis.

The authors provide an entertaining list of the acid-producing potential of more than 100 foods. As they put it, “flesh foods”- beef, chicken and fish – produce the most acid, with grains coming in second.

Dairy, oddly, is low-acid, except for cheeses. They produce the most. Four ounces of Parmesan, for example, yield 34 milliequivalents (mEq). Compare this to 4 ounces of trout (11 mEq), beef (8), cornflakes (6) or yogurt (1).

Acidity depends largely, but not exclusively, on protein content. All proteins form acid, but “flesh” proteins yield more. They contain more sulfurous amino acids than do plant proteins. Meat and grains also have more acid-forming phosphates.

In contrast, fruits and vegetables contain loads of alkali-producing potassium and magnesium. They have minus numbers: apples (-2 mEq), potatoes and cauliflower (-4), and avocados (-8), with the alkali prize going to raisins (-21).

To prove this theory, research must demonstrate four things: foods have differential effects on urine pH, acid-producing diets cause calcium to be excreted, calcium excretion reflects loss of calcium from bones, and acid-induced calcium losses lead to osteoporosis.

Research easily confirms that animal foods and grains produce more acid than do fruits and vegetables and cause calcium to be excreted in urine. Evidence for everything else, however, is much less certain. Although some studies find bone losses with high-acid diets, a recent “meta-analysis” published in the Journal of Bone Mineral Research concluded that urine calcium does not reflect bone calcium. It found little justification for the idea that alkaline foods prevent bone calcium losses.

Kidney specialists agree. I asked Dr. Jerome Lowenstein, author of “Acids and Basics: A Guide to Understanding Acid-Base Disorders,” for comment. He says bone calcium is involved in maintaining normal blood pH, but so are many other factors.

Normal kidneys maintain normal blood pH over a very wide range of diets. Diet may affect acid-base balance in people with damaged or diseased kidneys, but matters less to people with normal kidneys. Bone losses do occur in kidney disease but not because bone serves as an acid buffer.

“If it did, patients with advanced kidney disease would become invertebrate within a couple of years,” he says.

How to make sense of this? To prevent osteoporosis, the authors promote a vegan diet based on low-acid fruits, vegetables and beans, with no or minimal acid-producing meat, poultry, fish, eggs, cheese and grains.

Revolutionary? Hardly.

Last month’s report from the 2010 Dietary Guidelines Advisory Committee called for a shift in food intake patterns to a more plant-based diet, one with more vegetables, beans, fruits, whole grains, nuts, seeds, seafood and low-fat milk products, and only moderate amounts of lean meats, poultry and eggs.

Eat healthfully, and you automatically eat low-acid.

So: eat vegetables with your meat, forget about pH testing, and enjoy your dinner.

This article appeared yesterday in the Datebook section.  The dogs loved the food—a huge relief because we had not tested the recipes (oops).

Photos by Russell Yip. Aussies borrowed.

Challenging the pet-food dogma

Meredith May, San Francisco Chronicle, June 23, 2010

In her best-selling food industry exposés “What to Eat” and “Food Politics,” Marion Nestle taught the nation how to shop smarter at the supermarket. Now the New York University nutrition professor and Chronicle Food Matters columnist has teamed with animal nutrition expert Malden C. Nesheim to examine the $18 billion pet food industry in “Feed Your Pet Right: The Authoritative Guide to Feeding Your Dog and Cat” (Simon & Schuster; $16.99).

Their research-based work examines the politics, marketing and science behind pet food, and offers pet owners advice on how best to feed America’s 172 million cats and dogs. She recently visited The Chronicle’s test kitchen, where canine tasters wolfed down an easy-to-prepare recipe from the book.

Q: This book began when you couldn’t understand the ingredients on pet food labels?

A: I couldn’t! I was in a supermarket in Ithaca (N.Y.), and the pet food aisle was 120 feet long. I was stunned by the amount of real estate devoted to it. This had to be some huge industry, and it surprised me because I didn’t think dogs and cats had taken over the world. I looked at the label and it didn’t make any sense at all: stuff about guaranteed analysis, profiles and health claims all over it. We gathered all the books we could find on feeding pets, and they were so dogmatic – saying you have to feed your pet this one way and everything else was poison. They were enormously contradictory, and none seemed to be based on actual research.

Q: Is it in the best interest of the pet food industry to confuse us?

A: Of course – they are selling products that are inexpensive to make and profitable to sell, and all they have to do is convince pet owners if they don’t use their products, they are making a big mistake.

They would prefer you don’t think about what’s in there – the byproducts of human food products. There are billions of pounds of leftover parts of cows, pigs, chickens and sheep after they are slaughtered for human consumption, and something has to be done with it or it will be wasted. One way is to feed it to dogs and cats. They don’t care what part of the animal it comes from.

Q: Give us a cheat sheet. What should we look for on the label?

A: If you want one-stop shopping that meets all the nutritional needs of your cat or dog, look for the words “complete and balanced” on the package. That’s code for meeting all the nutritional standards set by the Association of American Feed Control Officials (AAFCO) – the non-regulatory agency that sets the pet food standards.

Next is the ingredient list. Our rule of thumb is to check the first five ingredients; after that, the ingredients are so small, they do not amount to much. The first five should be real foods – not wheat gluten or something that doesn’t sound like real food. A lot have meat byproducts in them that are quite nutritious, but a lot of people think they are disgusting.

Beyond that, if you are concerned about the quality and interested in organic, seasonal and locally grown, you can find a commercial pet food that meets those standards, but typically you will pay more.

Q: Is there some truth to the claims that some foods are for aging pets, puppies, weight loss, organic, premium?

A: You can pretty much trust it the way you can human food labeling. There will be cheats every now and then.

Q: Is price an indicator of quality?

A: We were rather surprised by what we found. We bought a collection of chicken dinners for pets that were all premium brands, which is a code for higher price. We compared the first five ingredients, the health claims and price, and although the ingredients were all the same, there was a threefold increase in price. So there’s some heavy marketing going on here. The word “premium” has no regulatory meaning, so you have to read what’s in the product.

Q: What are the main things we are doing wrong when it comes to feeding our pets?

A: Overfeeding.

Q: Should we just be cooking for our pets?

A: People who do say it is healthier. One of the funniest things we found was a big clinical research book for cats and dogs put out by Hills Co. that had a very long chapter about how dangerous it is to cook for your pets, then it gave generic recipes for cat and dog food that were easy to follow. We put the recipes in our book!

Q: Since the invention of commercial pet food, is there any evidence that pets are healthier or living longer? Or the opposite?

A: We were curious what did people do before commercial pet food. But there was little information and an astonishing lack of research about pet life spans. In the last 10 years, there’s been some preliminary evidence that life spans of dogs and cats have increased a little bit, but I wouldn’t want to push that too hard. There’s certainly evidence that pets are not doing any worse since commercial pet food was invented.

Q: The top five pet food companies control 80 percent of the market – who is regulating them?

A: All of those five companies are also either human food companies or consumer product companies. Governing them is a complicated regulatory system comprised of the (Food and Drug Administration’s) Center for Veterinary Medicine, AAFCO and states. States have their own rules, AAFCO sets models it wishes all states would follow but about half do, and the FDA regulation is minimal. But that’s changing.

Q: Is that because of the pet food recalls in 2007 that were traced to melamine in China?

A: Yes, it made everyone realize we only have one food supply – and it feeds humans, pets and farm animals. If we have a problem with pet food, then there will likely be a problem with all food. Sure enough, melamine showed up in baby formula in China and in a lot of products that were supposed to be containing milk. We need a food-safety system covering the whole thing, and the FDA is not unsympathetic to that approach. We need food labels on pet food that we can read, and calorie counts should be on them.

Q: What foods are deadly to pets?

A: Raisins, grapes or macadamia nuts, onions, garlic and chocolate. Little amounts really won’t do any harm; it’s pounds that causes problems.

Q: If you want to cook for your pet, how do you do it properly?

A: Follow a recipe.

Q: On your book tour, what are the most common questions people have?

A: A lot of questions about poop and how to keep the amount down – all these people in Manhattan apartments want to know. I tell them feed a high-premium, low-residue product with not much fiber in it. PetCo even has a sign showing the poop size comparisons using these kinds of products.

Recipes: Homemade food that gives pets the nutrition they need. E5

Homemade Dog Food

From “Feed Your Pet Right,” by Marion Nestle and Malden C. Nesheim (Simon and Schuster; $16.99). This recipe, adapted from guidelines in “Small Animal Clinical Nutrition” (2000), feeds one 40-pound dog. Amounts should be adjusted to the size, age and condition of the animal.

• 8 ounces cooked grains (rice, cornmeal, oatmeal, pasta and other grains and cereals)
• 4 ounces cooked meat (beef, lamb, pork, chicken, turkey, fish)
• 2 teaspoons fat (beef fat, chicken fat, vegetable oil, olive oil, fish oil)
• 1 ounce raw or cooked vegetables
• 1 teaspoon bone meal (or dicalcium phosphate supplement, see Note)
• 1/4 teaspoon potassium chloride supplement (salt substitute)
• 1 human adult daily multi-vitamin, multi-mineral tablet

Instructions: Combine the ingredients in a bowl. Mix well and serve.

My latest San Francisco Chronicle column is about calorie labeling going national and what the FDA is going to have to do to write regulations that make it work effectively.

While we are waiting for all that, how about what Burgerville is doing.  Burgerville, a fast-food chain in the Pacific Northwest, now does personalized calorie counts.  When you get your food, your receipt displays the calories for each item you ordered.  It also makes suggestions for ordering lower calorie items: “if you like the blueberry shake, you might consider getting a blueberry smoothie next time.”

Will doing something after-the-fact like this affect future food choices?  Researchers: get busy!

Two articles I’ve written are in journals this week: a short one in Newsweek (!) and my monthly Food Matters column in the San Francisco Chronicle.

New York’s Calorie Counts: A Good National Model (Newsweek, April 30 online and May 10 in print)

The new health-care law contains an overlooked boost for nutritionists like me: by next year, all national chains with more than 20 locations must offer “clear and conspicuous” calorie information. It’s the most important obesity-related public policy since the USDA’s food pyramid. But reception to the new mandate has been muted so far, largely because the benefits of New York City’s similar 2008 law seem minor: one study found just 15 fewer calories were consumed per meal; another reported it was 30; and a third found that people ate more.

The problem with these studies is that they focus on Starbucks customers and fast-food goers in low-income neighborhoods—patrons who often care about convenience and value above all. They also fail to capture the long-term benefits of calorie counting, namely education and social pressure. Labels will offer case-by-case lessons in exactly what 1,000 calories looks like, and they may even spur restaurants to ease up on sugar and fat. (Denny’s, McDonald’s, and Cosi, among others, have debuted lighter fare in New York City.) Of course, much depends on the definition of “clear and conspicuous.” Still, the country’s nutritional literacy is about to improve—making my job a lot easier.

Sugary school meals hit lobbyists’ sweet spot (San Francisco Chronicle, Sunday, May 2)

Nutrition and public policy expert Marion Nestle answers readers’ questions in this monthly column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: I’m stunned by the amount of sugar my daughter is served routinely in school: candied cereals, flavored milk, Pop Tarts, breakfast cookies, fruit juice – 15 teaspoons of sugar, just in breakfast. Why no standards for regulating sugar in school meals, especially when obesity and diabetes are such concerns?

A: Politics, of course. The U.S. Department of Agriculture spends $12 billion a year on school meals. Kids buy foods from snack carts and vending machines. Food companies fight fiercely to protect their shares in that bounty.

If you watched “Jamie Oliver’s Food Revolution,” you witnessed the struggle to get sugary foods out of schools. Fifteen teaspoons – 60 grams and 240 calories – is a lot for breakfast, but kids get even more sugar from snacks, treats from teachers and birthday cupcakes.

Sugars were never a problem when we supported school lunch programs decently. That changed when schools ran out of money, sought vending contracts with soft drink companies and encouraged kids to buy sodas and snacks. Schools evaded restrictions on snack sales during lunch periods. Nobody paid much attention to what kids ate in schools – until kids began getting fatter.

Why no standards? Nobody wants to take on the sugar lobbyists.

In 1977, a Senate committee recommended an upper limit of 10 percent of calories from added sugars. This was so controversial that from 1980 to 2000, the Dietary Guidelines gave no percentages when they said “eat less sugar.” The 1992 food pyramid said “Use sugars only in moderation.” It defined moderation in teaspoons – for example, 12 a day in a diet of 2,200 calories, which comes to less than 10 percent of calories. By then, health officials in at least 30 countries had adopted the 10 percent sugar guideline.

A committee of the Institute of Medicine undermined that consensus. Because science provides only circumstantial evidence for the effects of sugars on obesity and other health problems, the committee suggested a safe maximum of 25 percent of calories. Sugar trade associations happily interpreted this percentage as a recommendation.

In 2003, the World Health Organization issued a research report restating the 10 percent guideline. Using the IOM report as evidence, sugar trade associations enlisted senators from sugar-growing states to lobby U.S. government officials to withdraw funding from WHO. They also lobbied governments of sugar-growing countries to oppose the 10 percent guideline. WHO dropped the 10 percent sugar guideline.

Dietary guidelines are the basis of federal nutrition policy. The 2005 guidelines advised limits on sugars without stating a percentage. In a footnote, the guidelines said that sugars could be part of a day’s “discretionary calories,” defined as 2 to 8 teaspoons a day. This is less than 10 percent of calories, but the guidelines do not say so explicitly.

Neither does the USDA’s 2005 pyramid, which personalizes diet plans based on age, activity level and gender. I, for example, am allowed 195 discretionary calories for added fats and sugars. If I use them all for sugars, I get to eat 12 teaspoons – about 10 percent of my daily calories. This is less than the amount your daughter ate for breakfast or the sugars in a 20-ounce soda. Hence: lobbying.

Will we get an explicit sugar policy when Congress gets around to reauthorizing the Child Nutrition Act? The draft bill says nothing about sugars but does require school foods to adhere to “science-based” nutrition standards based on the dietary guidelines. If so, this means a maximum of 10 percent of calories from added sugars.

The IOM has just released a “School Meals” report. This says that with careful planning, 10 percent should provide enough sugar discretionary calories to permit sweetened low-fat milk, yogurt and breakfast cereals. The IOM warns that without these sweetened foods, student participation rates and nutrient intakes might decline.

Sorry, but I don’t buy the “kids won’t eat it” argument. I’ve seen plenty of schools where kids eat unsweetened foods. Somehow, they survive. Kids will eat healthier foods when meals are prepared by adults who care what kids eat, as Oliver has demonstrated.

As for legislation, California led the way with the 2007 school food nutrition standards bill, which regulated soda sales and the amount of sugar in snacks. Companies responded by reducing the sugars in their products. Passing the Child Nutrition Act will help, but its big drawback is funding. The draft bill increases school reimbursements by only about 6 cents per meal, not enough to meet costs in many school districts and much less than the $1 increase that many believe necessary.

But with luck, 2010 will bring us national legislation and improved editions of the dietary guidelines and pyramid. Let’s hope these make it easier for schools to help kids cut down on sugars.

Note: Nestle and Malden Nesheim will speak about their new book, “Feed Your Pet Right,” at 3 p.m. May 22 at Omnivore Books in San Francisco and at 3 p.m. May 23 at Point Reyes Books in Point Reyes Station.  Addition: Holistic Hound, Berkeley, Tuesday, May 18, 6:30 p.m.

Marion Nestle is the author of “Food Politics,” “Safe Food” and “What to Eat,” and is a professor in the nutrition, food studies and public health department at New York University. E-mail her at food@sfchronicle.com and read her previous columns at sfgate.com/food.  This article appeared on page K – 8.

Today is Easter Sunday and my monthly San Francisco Chronicle column appears today.  It deals with Michelle Obama’s campaign against childhood obesity.  Enjoy!

Kudos for first lady’s anti-obesity campaign

Nutrition and public policy expert Marion Nestle answers readers’ questions in this monthly column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: What do you think of Mrs. Obama’s “Let’s Move” campaign against childhood obesity? It doesn’t say much about junk food or food marketing. Isn’t this a cop-out?

A: Skeptic that I usually am, I have nothing but applause for Michelle Obama’s decision to adopt childhood obesity as the first lady’s official cause. Lady Bird Johnson’s legacy is the flowers that bloom throughout the nation’s capital. Obama must want hers to be the flowering of better health for our nation’s children.

Yes, Obama is sensitive to political realities. She calls her campaign “Let’s Move” rather than “Let’s Eat Less Junk Food.” But its goals are crystal clear. Her campaign aims to improve food in schools and eliminate “food desert” areas without access to healthier foods.

The White House organic garden is an integral part of this effort. It is no accident that Will Allen, the charismatic head of Growing Power, the group that runs urban farms in Milwaukee and Chicago, spoke at the campaign news conference. Good food, he said, is about social justice. Every child should have access to good food.

This campaign reveals real leadership on a desperately important issue. Obama brings diverse groups to this table. She presses government agencies to take action. She exacts promises from Congress to make it easier for kids to eat low-cost meals in schools. She got her husband to create a task force to tackle ways to prevent childhood obesity.

In addition, she is asking professional and business groups to do more to help kids eat better. I’m particularly impressed by her speech to the Grocery Manufacturers Association, which represents the makers of processed foods and beverages.

With masterful tact, Obama nonetheless insisted that the association “entirely rethink the products that you’re offering, the information that you provide about these products, and how you market those products to our children.” We parents, she said, want assurance that food companies will stop “teaching kids that it’s good to have salty, sugary food and snacks every day.”

Yes, she avoids saying anything about soda taxes or other measures that might make it easier for kids and parents to make better food choices, but she is bringing childhood obesity to public attention in a fresh, new way.

Consider what her campaign is up against. Preventing obesity means eating less, often a lot less, of processed fast-food, snacks and sodas. This puts the makers of such foods in an impossible bind. Eating less is not good for business.

Short of going out of business, what can such companies do to help? They can reformulate their products to make them a little healthier. They can stop marketing their products directly to children. But this, too, is bad for business – unless it can be used for public relations.

Indeed, food and beverage companies are falling all over themselves – with much fanfare – to reformulate and to promise to restrict marketing that targets kids.

PepsiCo, the maker of soft drinks and Frito-Lay snacks, says it will stop pushing sales of full-sugar soft drinks to primary and secondary schools worldwide by 2012. The new policy is voluntary, encourages rather than mandates, and assures school districts in the United States and abroad that the company will not tell them what to supply.

It keeps vending machines in schools and allows for continued sales of branded sugary drinks such as Gatorade, juice drinks, and sweetened milk.

Kraft Foods says it will reduce the sodium in its foods by 10 percent, also by 2012. This sounds good, but has a long way to go. Kraft’s Macaroni & Cheese (the SpongeBob package) contains 580 mg sodium per serving and two servings per package. A 10 percent reduction takes 1,160 mg sodium down to 1,050 mg. Salt is 40 percent sodium, so this brings salt down to 2.6 grams – about half a day’s upper limit for adults.

Still, these are steps in the right direction. Are they meaningful? You decide.

In the meantime, the Center for Responsive Politics, a nonprofit research group focused on the effect of money on public policy, says soda companies have increased by ten-fold the amount of money they spend on lobbying – no doubt to counter the threat of soda taxes.

What are we to make of these responses? They raise my favorite philosophical question: “Is a slightly better-for-you processed food necessarily a good choice?”

What would be better for preventing childhood obesity would be to make eating real foods the default. These, as defined by Oakland’s Prevention Institute, are relatively unprocessed foods that contain nothing artificial. And they are produced in ways that are good for farmworkers, farm animals and the environment, and are available and affordable to all.

Getting to that point requires policy as well as voluntary actions. Perhaps I’m reading too much into Obama’s campaign, but that’s how I interpret it. I’m supporting it. How about you?

My most recent column in the San Francisco Chronicle appeared later than usual (March 14) so I forgot to post it when it came out.  It deals with Listeria in pregnancy:

A guide to avoiding Listeria

Nutrition and public policy expert Marion Nestle answers readers’ questions in this monthly column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: I miscarried at 19 weeks of pregnancy. My doctor said my placenta was infected with Listeria, only her second case in 20 years of practice. I am your typical Bay Area food lover. I thought if I knew the sources of most of my food, I’d be safe. What is safe for pregnant women to eat in the post-Michael Pollan era?

A: Thanks for allowing your personal tragedy to alert others to this hazard. Losing a wanted pregnancy is a heartbreak. Losing one to a food-borne illness is especially tragic. Such illnesses should be preventable.

Food should be safe before it gets to you. That it sometimes is not is a consequence of our inadequate food safety system, which does not require food producers to test for harmful bacteria. The House of Representatives passed legislation that does so last summer, but the Senate is sitting on it. As an individual, you cannot easily protect yourself against invisible hazards in food. Congress must pass that legislation.

Without federal requirements, you are on your own to keep yourself and your unborn infant safe from food pathogens, especially Listeria. Much as I hate to add to what the French sociologist Claude Fischler calls “Listeria bacteria hysteria,” I must. Listeria preferentially affects pregnant women. If you are pregnant and want to stay pregnant, you must avoid Listeria.

This will not be easy. Listeria is widely dispersed in foods. Infections from it may be rare, but they are deadly. Listeria kills a shocking 25 percent of those it infects and is particularly lethal to fetuses.

Most people, including pregnant women, are immune to Listeria and do not feel ill when infected. But unlike most bacteria, Listeria penetrates the placenta, and fetuses have no immunity. The first sign of an infection can be a miscarriage or stillborn infant – too late for antibiotics.

How worried should pregnant women be about Listeria? Given our ineffective food safety system, I’d advise caution. The Centers for Disease Control and Prevention report 2,500 cases a year and 500 deaths. These numbers are minuscule – unless your pregnancy is affected.

Cases occur mainly among the young, the old and others with poor immunity. But the cause of miscarriages is not typically investigated, and I’m guessing that fetal deaths from Listeria are badly underreported.

Animals and people often excrete Listeria from their digestive tracts, even when they show no signs of illness. The bacteria get into food from infected animal waste and unwashed hands.

As a result, unpasteurized milk products and contaminated raw vegetables are frequent food sources. Other sources depend on yet another of Listeria’s nasty features – Listeria grows, reproduces and flourishes at refrigerator temperatures that stop other bacteria cold.

This explains why the CDC strongly advises pregnant women not to eat potentially undercooked foods stored in refrigerators: hot dogs, lunch meats, deli meats, patés, meat spreads and smoked seafood (salmon, trout, lox, jerky); soft cheeses such as feta, Brie, Camembert, those with blue veins, and especially Mexican “queso blanco fresco”; and raw milk or foods containing unpasteurized milk.

Even though some of these foods were cooked or pasteurized to begin with – blue cheese, for example – they can become contaminated after processing. Days or weeks of refrigeration give Listeria ample time to reproduce. Just about any food sitting around in a refrigerated package can be a source, with meat, fish and dairy foods especially suspect.

The CDC advises following safe food handling procedures to the letter at home. Avoid cross-contaminating raw and cooked foods, and use refrigerated perishables right away.

Listeria infections were virtually unknown 25 years ago, so view this hazard as collateral damage from the consolidation and centralization of our industrialized food supply.

Do not despair. There is some good news. Cooking kills Listeria. Pregnant women still have plenty of options for good things to eat that are safe.

Anything cooked hot is safe. So are hard cheeses, semisoft cheeses like mozzarella, pasteurized processed cheeses, and cream and cottage cheeses. These were cooked or are now too dry and salty for bacterial growth. Anything canned – patés, meat spreads, smoked fish, other fish – also is safe.

When it comes to food hazards during pregnancy, Listeria is unique. A sip of wine every now and then is not going to induce fetal alcohol syndrome, nor will your baby get mercury-induced brain damage from an occasional tuna sandwich. The risks from such hazards accumulate with amounts consumed over time.

But the risk from Listeria is acute. With so much at stake, and so many other food choices available, why take chances?

Just last month, the Food and Drug Administration reported recalls of queso fresco, blue cheese and bean sprouts because of possible Listeria risk. The FDA is doing its best, short of legislation. To keep Listeria out of the food supply, Congress needs to act. Write your representatives now.

Marion Nestle is the author of “Food Politics, “Safe Food” and “What to Eat,” and is a professor in the nutrition, food studies and public health department at New York University. E-mail her at food@sfchronicle.com and read her previous columns at sfgate.com/food.

My post on vegetarian and vegan diets elicited so many comments that I thought it was worth recycling for my monthly (first Sunday) column in the San Francisco Chronicle.  It appeared today.

My San Francisco Chronicle column, now appearing in print on the first Sunday of the month, is also online.

Its title:  “Hot food issues ready to boil over this year.”

Q: What do you think will happen with food and nutrition in 2010?

A: I wish I could read the leaves while I drink tea, but the best I can do is tell you which issues I’m going to be watching closely this year.

Hunter Public Relations recently asked 1,000 Americans which food-related issues they thought were most important in 2009. The top three? Food safety, hunger and food prices. For the decade, the winner was childhood obesity.

I have my own top 10 list of hot-button issues for 2010, and here they are:

• Hunger: More than 35 million Americans get benefits to which they are entitled under the Supplemental Nutrition Assistance Program (formerly, food stamps). The economy may be improving, but not quickly enough for millions who have lost jobs, health care and housing. Will Congress do anything this year to strengthen the safety net for the poor? It needs to.
• Childhood obesity: Rates of childhood obesity may have stabilized, but we all want to figure out how to prevent kids from gaining so much weight that they develop adult chronic diseases. I expect to see more efforts to improve school food and make neighborhoods more conducive to walking to school, riding bikes and playing outside.
• Food safety regulation: Congress is sitting on a bill to give the Food and Drug Administration some real authority for food safety. The bill does not do what is most needed – establish a single food-safety agency – but is a reasonable step in the right direction. Let’s hope Congress gets to it soon.
• Food advertising and labels: The long-dormant FDA and Federal Trade Commission are getting busy at last. In the wake of the Smart Choices fiasco, the FDA is working to make package labels less misleading and easier to understand. The agencies have proposed nutrition standards for products marketed to children. These voluntary standards fall far short of my preference – an outright ban on marketing junk foods to kids – but puts food companies on notice that their products are under scrutiny. The FDA is also working on designs for front-of-package labels. I’m hoping it chooses a “traffic-light” system that marks foods with a green (any time), yellow (sometimes) or red (hardly ever) dot. Expect plenty of opposition from the makers of red-dotted products.
• Meat: The meat industry has been under fire for raising food animals under inhumane conditions, using unnecessary hormones and antibiotics, mistreating immigrant labor, and polluting soil and water. Now it is also under fire for contributing to climate change. Recent films like “Food, Inc.” and “Fresh” and books such as Jonathan Safran Foer’s “Eating Animals” are encouraging people to become vegetarians or to eat less meat to promote the health of people and the planet. I’ll bet the meat industry pushes back hard on this one.
• Sustainable agriculture: The back-to-the land movement has loads of people buying local food, choosing foods produced under more sustainable conditions and growing their own food. The number of small farms in America increased last year for the first time in a century. Seed companies cannot keep up with the demand. It will be fun to follow what happens with this trend.
• Genetically modified (GM) foods: My book, “Safe Food,” comes out in a new edition this year, so I am paying especially close attention to debates about GM foods. The FDA’s 1994 decision to prohibit labeling of GM foods continues to haunt the food biotechnology industry. By now, nearly all American soybeans and sugar beets (95 percent) are GM, as is most corn (60 percent). But when the U.S. Department of Agriculture approved GM sugar beets in 2005, it neglected to perform the required environmental impact assessment. On that basis, environmental groups want to ban further planting of GM sugar beets. The dispute is now in the courts.
• Chemical contaminants: The FDA has yet to release its report on the safety of bisphenol A, the plastic chemical that acts as an endocrine disrupter. Shouldn’t it be banned? The bottling industry says no. Watch for fierce arguments over this one.
• Salt: Nutrition standards allow 480 mg sodium (the equivalent of more than 1 gram of salt) per serving. A half cup of canned soup provides that much. A whole cup gives you 4 grams and the whole can gives you 8 grams – much more than anyone needs. Nearly 80 percent of salt in American diets comes from processed and restaurant foods. Companies are under pressure to cut down on salt. Will they? Only if they have to.
• Dietary advice: The new edition of Dietary Guidelines for Americans, which the government publishes every five years, is due this year. What will it say? I can’t wait to find out.

Those are the issues I am tracking these days. My one crystal-ball prediction? We will be hearing a lot more about them this year.

Happy new year!

My latest column in the San Francisco Chronicle deals with the immunity health claim on boxes of Kellogg Cocoa Krispies (see previous posts).  I’ve been writing the column for the last year at irregular intervals of about once every three weeks.  Beginning in January 2010, it has its own slot and will appear on the first Sunday of the month.  Here’s this one:

Q: It’s great that San Francisco City Attorney Dennis Herrera put a stop to the absurd “immunity” claim on Kellogg’s Cocoa Krispies, but how do companies get away with this?

A: I confess; I’m a health-claims junkie. I snatched up the immunity-claiming box of Cocoa Krispies the minute I saw it in a supermarket last August. I consider it a treasure: “Now helps support your child’s IMMUNITY.”

How does Cocoa Krispies perform this miracle? The cereal contains 25 percent of the daily value of antioxidant vitamins A, B, C and E per serving instead of the old 10 percent. Vitamins, Kellogg points out, play an important role in immunity.

Of course they do. All nutrients are involved in immune function. But is it remotely possible that Cocoa Krispies might protect your child against colds or swine flu? I wish.

Antioxidants present an unparalleled marketing opportunity. Kellogg does not have to prove that its cereals are protective. Immunity claims fall into a Food and Drug Administration regulatory gray area. “Supports immunity” is a “structure-function” claim, so called because it promises to support a structure or function of the human body. However you might interpret such claims, they do not really promise to prevent, treat or cure disease.

Congress expressly authorized structure-function claims when it deregulated dietary supplements in 1994. But that law did not apply to foods. Food companies wanted to use these claims, too. At first the FDA balked. When faced with further legislation and court overturns, the FDA gave up. Now it merely says that structure-function claims on supplements must be truthful and not misleading. The FDA says nothing about structure-function claims on food products. It mostly looks away when they appear.

“Misleading” is inevitably in the eye of the beholder. Herrera turns out to be a skeptic.

“The Immunity claims,” he said, “may falsely suggest to parents that cereals like Cocoa Krispies are more healthy for their children than other breakfast foods … [and] mislead parents into believing that serving this sugary cereal will actually boost their child’s immunity.” Kellogg, he said, must produce the evidence or have the claim subject to “immediate termination or modification.”

Faced with this threat and with ridicule in the press, Kellogg wisely decided to phase out the immunity-labeled Cocoa Krispies packages. Consider them collectors’ items.

Much is at stake. Ready-to-eat cereals produce more than $8 billion a year in sales. Kellogg spent about $32 million in 2008 to promote Rice Krispies cereals, and $4 million of that amount went to advertise Cocoa Krispies alone.

Shoppers care about health. If cereals can be advertised with special health benefits, more boxes will fly off the shelves. Food companies consider health claims essential for marketing their products.

This explains why so many companies are adding omega-3 fats, probiotics and antioxidants to so many foods. These ingredients make foods “functional,” meaning that the foods contain something beyond their usual nutritional value. Although little evidence shows that functional foods make healthy people healthier, companies can use functional ingredients to make health claims, no matter how far-fetched. These days, functional foods are about the only processed foods with increasing sales.

Kellogg has plenty of company with functional ingredients and health claims. See, for example, the claims on Nestlé (no relation) Juicy Juice products targeted to toddlers. One product adds antioxidants to “help support immunity.” The other adds omega-3s to “aid brain development.”

Think about it: Will feeding your toddler a sugary juice product really make her smarter? Face it. You are not supposed to think about it. You are supposed to buy – and feel good about doing so.

Absent the FDA, Herrera stepped into the breach. He does not care whether the claims are on Kellogg cereals or Juicy Juice cartons. If companies make such claims, he insists that they produce the evidence for them.

This will not be easy to do. It is one thing to find evidence that specific nutrients are involved in immune function. It is quite another to show that people who eat sweetened cereals or juices containing such nutrients are healthier than those who do not.

That is why the European Food Standards Agency denied hundreds of company petitions for health claims. The agency cannot find much evidence for the health benefits of foods with added functional ingredients. Its decisions have put European food marketers into crisis. How are they supposed to sell products without health claims?

As I keep saying, health claims are about marketing, not health. If it were up to me, I would remove all health claims from food packages. Foods are not drugs. Health claims cannot help but mislead.

So let’s congratulate Herrera for filling a regulatory gap. His colleagues – and the press – are doing their job on this one. FDA: Get to work!