by Marion Nestle

Currently browsing posts about: Diets

Sep 4 2014

The diet wars: same old, same old

To my great surprise, a new clinical trial finding that low-carbohydrate diets help people lose weight has been getting a lot of press. Its conclusion:

The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors.

This is news?

The trial, conducted by authors who previously published a meta-analysis that came to the same conclusion, told people to eat either a low-carbohydrate diet of less than 40 grams a day (the amount of sugar in one 12-ounce soda) or a “low-fat” diet of 30% of calories from fat or less.

They didn’t do either, of course (for one critic’s analysis, see examine.com).

I put quotes around “low-fat” because 30% of calories is not exactly what I would call low—lower, for sure, but not low. After a year, the low-carb dieters lost about 3.5 kg more than did the “low-fat” dieters.  They also showed greater improvements in their risk factors for cardiovascular disease.

As I told Andy Bellatti

The folks eating the low carbohydrate diet…were eating less, and probably a lot less.  It’s easier for some people to lose weight if they cut out whole categories of food, in this case, carbohydrates.  But is this a long-term solution?  For that, we need to see results for several years.   Studies that examine the effects of different kinds of diets—and there have been many—typically find that all work to the extent that they cut calories, but that people have trouble sticking to extreme diets, which the low-carb one was in this study.  Personally, I like carbs and would rather cut my calories some other way, but that’s just me.  The bottom line: if you want to lose weight and are having trouble doing it, you need to eat less.

This profoundly boring conclusion, discussed at length in my book with Malden Nesheim, Why Calories Count: From Science to Politics, has just been confirmed by yet another meta-analysis.  This one doesn’t seem to be getting much press, however.

It reports significant weight loss with any low-carbohydrate or low-fat diet.

Weight loss differences between individual named diets were small. This supports the practice of recommending any diet that a patient will adhere to in order to lose weight.

An accompanying editoria,  “A Diet by Any Other Name Is Still About Energy,” points out that study investigators only rarely analyze for how well participants in these studies actually adhere to the different diets, and for how long.

This makes it impossible for readers to figure out whether the weight loss was due to the specific components excluded from the diet or to the level of adherence.

In other words, whatever helps you eat less, helps you lose weight.  Go for it.

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Feb 17 2014

In Memorium: Sid Caesar

Thanks to Deborah Szekeley for forwarding this link to an evening in the 1950s when Sid Caesar, who died last week, went to dinner with Imogene Coca at a health food restaurant in New York.

Perhaps it is still open?

 

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Feb 14 2014

President’s Day Weekend Reading: The Diet Fix

Yoni Freedhoff.  The Diet Fix: Why Diets Fail and How to Make Yours Work.  Harmony Books, 2014.

Ordinarily I don’t pay much attention to diet books but this one comes from the Canadian obesity physician, Dr. Yoni Freedhoff, whose Weighty Matters blog is fun to read and well worth following.

The key to healthy dieting, he says, is to avoid dieting’s seven deadly sins: hunger, sacrifice, willpower, restriction, sweat, perfectionism, and denial.

This sounds hopeful.

Instead, you are to reset your relationship with food forever, starting with a 10-day preliminary experiment in which you get ready, keep a diary, banish hunger, cook, think, exercise, indulge, eat out, and set goals.  Then you move forward, one day at a time.

“You absolutely CAN do this,” he says.

This is a seriously mindful weight-loss program that works well for his patients.  It ought to.

Give it a try?

The book even comes with recipes.

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Jan 20 2014

How to get people to buy healthier food: cardboard cutouts?

Can it really be this easy?  Morrison’s, a grocery chain in the U.K., put cardboard cutouts of doctors near the produce section.

A new pilot scheme in a Morrisons store in Salford, using cardboard cut-outs of local GPs in the fresh produce aisles delivered a 20% rise in the sales of fresh fruit and a 30% uplift for frozen fruit.

All of this is part of Great Britain’s Public Health “Responsibility Deal,” which aims to enlist businesses to voluntarily promote health objectives.

The Responsibility Deal embodies the Government’s ambition for a more collaborative approach to tackling the challenges caused by our lifestyle choices.

Organisations signing up to the Responsibility Deal commit to taking action voluntarily to improve public health through their responsibilities as employers, as well as through their commercial actions and their community activities. Organisations can sign up to be either national partners or local partners.

The principles and ambitions of the Responsibility Deal are set out in its core commitments and supporting pledges.

This is all it takes?  Really?

Why do I think this won’t work nearly as well in America?  We have a long way to go, says the USDA.

What might work?  Celebrities?  Sports figures?  Political figures?

Jun 4 2013

Questions about food politics: iPhone apps and phytonutrients

I’m always happy to answer questions dealing with issues related to food politics.  Here are responses to two that came in last week.  I’ll do another two sometime this week. 

Q1.  I was just introduced to your book, What to Eat, and I read it, cover to cover, thoroughly enjoying each area of the market.  I am emailing in hopes that you have a suggested iPhone App, which suggests or promotes healthy eating.  Not so much calorie counter Apps, but Apps which make suggestions towards healthier options or perhaps even suggests macro or micronutrients which we may be lacking based on the foods we are purchasing and consuming.  Any help is much appreciated!  Thanks!

A.  I’m a diehard BlackBerry user and haven’t a clue.  Readers: suggestions?

Q2.  I’m an NYU MPH student and will probably be taking your Food Advocacy class next spring.  I adore your blog and as of late have been especially appreciative of your Farm Bill breakdowns. (What a confusing document!)  I was wondering what your take was on the NYTimes article that appeared in the Week in Review on Sunday titled, “Breeding the Nutrition out of Our Food” by Jo Robinson.  Have we really been losing the phytonutrients in our food since we became farmers?

A.  Ms. Robinson, whose terrific new book, “Eating on the Wild Side” is out this week, collected data on phytonutrient (plant antioxidant) levels in wild foods and their bred-to-be-less-bitter supermarket counterparts.  The wild ones have more, but they usually don’t taste as good.  The idea that foods now are less nutritious than foods in the past fits conveniently with concerns about our industrialized food system.  But data on trends in nutrient content are difficult to come by (the methods change over time), and differences in health benefits are impossible to assess.  The bottom line: people who eat fruits and vegetables—even supermarket varieties—are healthier than people who don’t.  Would they be even healthier if the vegetables were more bitter because of the phytonutrients?  Hard to say.  I’m going to eat my veggies and not worry about this one.

Apr 7 2013

The Mediterranean diet: a delicious way to prevent heart disease?

In my April (first Sunday) Food Matters column for the San Francisco Chronicle, I catch up with the Mediterranean diet study first published online on February 25 (and widely publicized), and just now in print in the New England Journal of Medicine.

Q: I read about a study (New England Journal of Medicine, April 4) claiming that Mediterranean diets prevent heart attacks. Does this mean I can stop worrying about eating pasta?

A: That study, alas, was not about pasta. It wasn’t really about Mediterranean diets, either. Instead, it was about the benefits of supplementing healthy, largely vegetarian diets with olive oil or nuts.

We usually think of Mediterranean diets as offering lots of vegetables and fruit, some fish or poultry, small amounts of pasta, olive oil as the main fat, everything cooked wonderfully and accompanied by wine.

For years, studies of such diets have shown them to be associated with much lower rates of heart disease than are typically found in groups following “Western” diets. Studies of the effects of individual components of Mediterranean diets, however, have not always yielded such consistent results.

Used a control group

In the study you are referring to, investigators in Spain advised two groups of participants to follow a Mediterranean diet, but a control group to eat a low-fat diet. Advising people to eat in a certain way does not necessarily mean that they will. To make sure the diets differed, the investigators divided the Mediterranean diet advisees into two groups.

At no cost to participants, they gave one group a liter of extra virgin olive oil a week, with instructions to use at least 4 tablespoons daily. They gave the other Mediterranean diet group an ounce of mixed nuts a day to eat at least three times a week. They measured biomarkers in the participants’ blood to confirm that they really ate the supplements.

The results were impressive. Although there were no differences in overall mortality in nearly five years, the two supplemented-Mediterranean diet groups displayed about a 30 percent reduction in the risk of heart attacks and strokes as compared with the group advised to eat a low-fat diet.

But, because they did not find much change in the participants’ dietary patterns, the investigators concluded that the extra virgin olive oil and nut supplements must have been responsible for the observed health benefits.

What does the Mediterranean dietary pattern have to do with these results? Extra virgin olive oil and nuts are components of this pattern. Both contain “good” fats, largely unsaturated or polyunsaturated, and both are high in certain phenolic antioxidants.

These features have been recognized for decades. The Mediterranean diet came to public attention in America in the early 1990s as a result of efforts of the International Olive Oil Council, a trade group established by the United Nations.

The council recruited a group in Boston, Oldways Preservation and Exchange Trust, to promote olive oil to American chefs, nutritionists and food writers. If, they said, we ate diets similar to those followed by the Greeks and southern Italians since ancient times, we might also achieve similar levels of health and longevity.

The council and Oldways based this idea on the results of research initiated soon after World War II. In the late 1940s, Rockefeller University sent investigators to the island of Crete to find out why its people, although living in extreme poverty, were so healthy. Once past infancy, people on Crete displayed the highest longevity in the world, rivaled only by the Japanese.

Subsequent Seven Countries studies conducted by Ancel Keys and his colleagues appeared to confirm the health benefits of Mediterranean dietary patterns.

Olive oil, nuts critical

Olive oil or nuts seem critical to these benefits. Besides their fat and phenol content, both are wonderful to eat. Olive oil tastes good by itself and it makes other foods, particularly vegetables, taste delicious. Nuts enliven any dish. So research on Mediterranean diets brought good news. You could eat delicious food – and it would be good for you.

The Mediterranean diet took hold. In the early 1990s, you had to search hard for a decent bottle of extra virgin olive oil; now almost any supermarket carries several brands, many of high quality. Except during the sad, but blessedly brief, low-carb era, the Mediterranean diet became mainstream.

But let’s be clear about what the Mediterranean diet is and is not. It is a model of the largely plant-based dietary pattern recommended by health agencies in the United States and worldwide. It does not mean supersize bowls of macaroni smothered in cheese.

Olive oil and nuts, for all their virtues, are loaded with calories. The Spanish study’s 4 tablespoons provide 400 calories. An ounce of mixed nuts is about 200. Include them in your diet by all means, but most definitely in moderation.

I think the best reason for following a Mediterranean diet is that its foods are terrific to eat. Pasta, vegetables, a fish, some good bread, and a glass of wine? Sounds good to me, any time.

Marion Nestle is the author of “Why Calories Count: From Science to Politics,” as well as “Food Politics” and “What to Eat,” among other books. She is a professor in the nutrition, food studies and public health department at New York University, and blogs at foodpolitics.com. E-mail:food@sfchronicle.com. 

Dec 12 2012

We eat what we buy. Both need improvement, says USDA.

USDA’s Economic Research Service has just issued a report, Assessing the Healthfulness of Consumers’ Grocery Purchases.

The bottom line?  Americans buy fewer fruits and vegetables than recommended but far more refined grains, sugars, and meat.

Here’s the summary diagram:

These results should not come as a surprise.  According to the 2010 Dietary Guidelines, the leading sources of calories in U.S. diets are:

  1. Grain-based desserts
  2. Breads
  3. Chicken and chicken dishes
  4. Sodas and other sugary beverages
  5. Pizza
  6. Alcoholic beverages
  7. Pasta and pasta dishes
  8. Tortillas, burritos, tacos
  9. Beef and beef dishes
  10. Dairy desserts
We eat what we buy (or are given).
That’s why congressional pressure to increase grains and meat in school lunches (see yesterday’s post) is questionable from a public health standpoint.
Aug 30 2012

Does starvation increase longevity? Not in monkeys.

The New York Times front page today has a report of a long-term study at NIH of severe calorie restriction in Rhesus monkeys.  It found that calorie restriction did not extend the monkeys’ lifespan.

I’m not at all surprised.  My co-author and I reviewed the literature on calorie restriction for a chapter in our book, Why Calories Count.

The new study makes news because it contradicts a study done in Wisconsin showing that severe calorie restriction extends life.  Severe means 25% to 30% fewer calories per day that are needed to maintain normal body weight.  I’d call this a starvation diet.

An editorial accompanying the report of the study in Nature attributes the difference between the results of this NIH trial and the Wisconsin study to a difference in dietary composition, suggesting that calories differ in their effects.

Not necessarily.  The Wisconsin study allowed the control monkeys to eat a lot of junk food and they were fatter than normal.  The NIH study restricted calorie intake in its control monkeys so they maintained normal weight and were healthier.  This is the simplest explanation of the difference.

Studies in rats, mice, and many other animals show that calorie restriction extends life.

But what about primates?

Starvation can hardly be good for health.  It causes weight loss, of course, but also a host of physiological and psychological problems.  These were extensively documented in humans during World War II in Ancel Keys’ Starvation studies.

The relationship between BMI and human longevity has been examined in several recent studies, all of which show similar results: Longevity is best associated with BMIs in the range considered normal or slightly overweight.  Above that range—but also below it—mortality increases.  

Being underweight is associated with higher mortality.

A Canadian study provides this example:

And one from the National Cancer Institute provides another:

The bottom line?  Eat a healthy diet and balance calories to maintain a healthy weight within that range.