by Marion Nestle

Currently browsing posts about: Calories

Aug 3 2011

Where did the 2,000 calorie diet idea come from?

I’m in the midst of working on the copy-edited manuscript of my forthcoming book with Malden Nesheim Why Calories Count: From Science to Politics (University of California Press, March 2012) and spending every minute I have on it.  So I’m going to take some shortcuts on the blog this week and deal with some questions I’ve been asked recently.

One is right on the topic of the book:

Q.  Could you address the 2,000 calorie a day number (both its history and speculate on how an individual can arrive at a more personalized amount)? Short of metabolic testing (and I read conflicting opinions on that, too), it seems rather difficult to figure out how much I should be eating.

A.  Nothing could be easier, and here’s a preview of the kind of thing that will be in this book (with footnotes, of course):

If you look at  a food label, you will see ingredient contents compared to a 2,000-calorie average diet: “Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.”

Here’s the history of where that came from:

The FDA wanted consumers to be able to compare the amounts of saturated fat and sodium to the maximum amounts recommended for a day’s intake—the Daily Values.  Because the allowable limits would vary according to the number of calories consumed, the FDA needed benchmarks for average calorie consumption, even though calorie requirements vary according to body size and other individual characteristics.

From USDA food consumption surveys of that era, the FDA knew that women typically reported consuming 1,600 to 2,200 calories a day, men 2,000 to 3,000, and children 1,800 to 2,500. But stating ranges on food labels would take up too much space and did not seem particularly helpful. The FDA proposed using a single standard of daily calorie intake—2,350 calories per day, based on USDA survey data. The agency requested public comments on this proposal and on alternative figures: 2,000, 2,300, and 2,400 calories per day.

Despite the observable fact that 2,350 calories per day is below the average requirements for either men or women obtained from doubly labeled water experiments, most of the people who responded to the comments judged the proposed benchmark too high. Nutrition educators worried that it would encourage overconsumption, be irrelevant to women who consume fewer calories, and permit overstatement of acceptable levels of “eat less” nutrients such as saturated fat and sodium. Instead, they proposed 2,000 calories as:

  • consistent with widely used food plans
  • close to the calorie requirements for postmenopausal women, the population group most prone to weight gain
  • a reasonably rounded-down value from 2,350 calories
  • easier to use than 2,350 and, therefore, a better tool for nutrition education

Whether a rounding down of nearly 20 percent is reasonable or not, the FDA ultimately viewed these arguments as persuasive. It agreed that 2,000 calories per day would be more likely to make it clear that people needed to tailor dietary recommendations to their own diets. The FDA wanted people to understand that they must adjust calorie intake according to age, sex, activity, and life stage. It addressed the adjustment problem by requiring the percent Daily Value footnote on food labels for diets of 2,000 and 2,500 calories per day, the range of average values reported in dietary intake surveys.

 As to how many calories you personally need, I think they are too difficult for most people to count accurately to bother.  The bottom line: If you are eating too many, you will be gaining weight.   

The best advice I can give is to get a scale and use it.  If your weight starts creeping up, you have to eat less.

The book will go into far more explanation of such issues but for that you will have to wait until March.


Jul 20 2011

Yes calories count, especially in big numbers

Center for Science in the Public Interest anounces its Xtreme Eating Awards and describes them in detail in the latest issue of Nutrition Action Healthletter.

Xtreme Eating gives the numbers for calories, saturated, fat and sodium (nicely summarized by  FoodNavigator), but let’s just look at calories.

  • Denny’s Fried Cheese Melt  1,260
  • The Cheesecake Factory Farmhouse Cheeseburger 1,530 (1,900 with fries)
  • IHOP Bacon ’N Beef Cheeseburger 1,250 (plus 620 for onion rings)
  • Cold Stone Creamery PB&C Shake 2,010
  • Applebee’s Provolone-Stuffed Meatballs With Fettuccine  1,520
  • The Cheesecake Factory Ultimate Red Velvet Cake Cheesecake 1,540
  • The Steakhouse (Morton’s) Porterhouse Steak and mash 1,390 for the steak; 850 for the mash
  • Great Steak extra large King Fries 1,500

These, it should be evident, are substantial fractions of the 2,000 to 3,000 calories most people need in a day.  And these numbers don’t include the additional calories from drinks and anything else that’s added.

CSPI gets sarcastic: “Let’s get one thing clear: Restaurants have nothing to do with the nation’s obesity epidemic. It’s not their fault that two out of three adults and one out of three children are either overweight or obese.”

Are the numbers accurate?  My July 20 JAMA hasn’t arrived yet but I hear that it has an article saying that the calorie numbers posted on restaurant menu boards seem close enough.

If an item says it’s 1,500 calories, it probably is.  Best to share with friends.

 

 

 

 

Jun 7 2011

Sedentary work and obesity: another view

On May 26, the New York Times published a report of a new study on causes of obesity.  The study examined changing rates of physical activity in the workplace. Its conclusion?  Sedentary work is a major cause of rising rates of obesity in the United States.

The shift translates to an average decline of 120 to 140 calories a day in physical activity, closely matching the nation’s steady weight gain over the past five decades, according to the report.

Eric Schlosser and I wrote a letter to the editor pointing out a few flaws in that argument.  The Times did not publish our letter, but here it is:

To the editor:

It makes sense that sedentary work is a factor in the current obesity epidemic (May 26). But it cannot be an important cause. The changing American workplace cannot explain why the obesity rate among the nation’s preschoolers has doubled in recent years and that among elementary schoolchildren has tripled.

The rise in obesity worldwide is linked to the embrace of the American diet, not to a decline in manufacturing.

In China, childhood obesity has increased at least five-fold since 1985.

Simplest explanations are usually best. Reversing obesity means eating less and making healthier food choices.

It also means making it easier to do that by setting policies that promote smaller portions, lower prices on fruits and vegetables, restrictions on marketing food to children, and healthier school meals.

Of course, an increase in well-paid manufacturing jobs would help too.

—Marion Nestle and Eric Schlosser

 

 

 

 

Apr 19 2010

KFC as a standard for fast food evaluation? The Double Down Gluttony Index

Statistician Nate Silver uses KFC’s nutritional analysis (which nobody seems to believe, for good reason, as you can see from the added note below) to create a Double Down Index for evaluating the nutritional quality of fast food based on fat, cholesterol, and sodium.

I’ve created an index based on the amount of fat, sodium and cholesterol that the Double Down and a variety of comparable sandwiches contain as a portion of the USDA daily allowance. (In the fat category, saturated fats are counted double and trans-fats are counted triple.) The index is scaled such that the Original Recipe version of the sandwich receives a score of 1.00, a measure of gluttony that will hereafter be known as The Double Down (DD).**

** To calculate Double Downs for your own favorite sandwich, apply the following formula: divide the number of mg of cholesterol by 469, the number of mg of sodium by 3,754, the number of grams of total fat by 133, the number of grams of saturated fat also by 133, and the number of grams of trans-fat by 66. Then sum the result.

He also calibrates Double Downs per Calorie (DDPC): “Take the above result, divide by the number of calories, and multiply by 540.”

His charts are great. Take a look.

Thanks to Richard Einhorn for sending.

Additional note: My NYU colleague Lisa Young, author of The Portion Teller, wrote the company to correct the calorie calculations.  She says:

I’ve done my own calculations for calories obtained from USDAs website….Even the grilled chicken version has nearly 600 calories, and that is without any sauce. Also the actual product looks bigger than the serving size info provided to me which would suggest that the breadless sandwich may even contain more calories than I have listed below.

2 3-oz pieces fried chicken = 441 kcal
2 slices Monterey Jack cheese (1 oz each)=211 kcal
2 slices bacon, medium, cooked= 87 kcal
TOTAL= 739 kcal

2 3-oz pieces grilled chicken = 282 kcal
2 slices Monterey Jack cheese (1 oz each)=211 kcal
2 slices bacon, medium, cooked= 87 kcal
TOTAL=580 kcal

Jan 6 2010

How many extra calories cause weight gain?

For years, some people – not me – have been saying that eating one extra 50-calorie cookie a day can make you put on 5 pounds per year.  This calculation comes from basic math: if about 3500 extra calories make you put on a pound of body fat, then 50 times 365 is 18,250 extra calories which, divided by 3500,  equals about 5 pounds.

This never made sense to me.  It is impossible to know how much you are eating each day within 50 calories let alone how many calories you are using in daily activities.  Yet people used to be able to keep their weight steady without thinking about calories at all.

This is because the body regulates weight and can easily compensate for such small changes in calorie intake or output with small changes in metabolic rate.  It takes more calories to move heavier bodies, and fewer to move lighter ones.

For years, I’ve been thinking that it must take a lot more than 50 extra calories a day – I guessed hundreds -  to make people gain weight.  I thought this for two reasons:

First reason: Portion sizes have increased greatly in recent years, and larger portions have more calories.  Sometimes, they have a lot more.  Foods eaten outside the home often have more calories in them than anyone suspects.

That’s why calorie labeling matters.  Labeling may underestimate the actual calories present in a food according to Tufts researchers (see this week’s Time for commentary and also see the industry response).  But even so, a new study shows that labeling encourages people to cut down on food intake, at least at Starbucks.  Make that two new studies: one from the Rudd Center at Yale comes to the same conclusion.

Second reason: I keep hearing from pediatricians who treat overweight kids that they have kids in their practices who drink from 1,000 to 2,000 calories a day from sodas alone.  I can’t judge whether these figures are correct or not, but several different kinds of studies suggest that many people today are eating a lot more calories than their counterparts of 25 years ago.

Now Martin Katan and David Ludwig have done the actual calculations in a paper in this week’s JAMA titled “Extra calories cause weight gain–but how much?”  Their conservative estimate is that it would take an excess of 370 calories to gain 35 pounds in 28 years.   To become obese in 25 years, you would need to eat 680 calories a day more than you expended.

To become 58 pounds overweight at age 17, they predict that a child would need to overconsume 700 to 1,000 calories a day from the age of 5 or so.

These figures are quite consistent with what those pediatricians were telling me.  By other estimates, average caloric intake has increased by 200-500 calories a day since the early 1980s, along with a 700 calorie-a-day rise in the availability of energy in the food supply (from 3,200 to 3,900 per day per capita).

As Katan and Ludwig conclude:

small changes in lifestyle would have a minor effect on obesity prevention.  Walking an extra mile a day expends, roughly an additional 60 kcal compared with resting – equal to the energy in a small cookie.  Physiological considerations suggest that the apparent energy imbalance for much of the US population is 5- to 10-fold greater, far beyond the ability of most individuals to address on a personal level.  Rather, an effective public health approach to obesity prevention will require fundamental changes in the food supply and the social infrastructure.

This is because on the personal level, prevention of weight gain means eating hundreds of calories a day less.  Moving more, useful as it is, will not do the trick unless people eat less as well.

On the societal level, we need measures to make it easier for people to eat less.

I can think of a bunch of examples.  You?

Sep 28 2009

The cost of obesity (and fixing it)

I don’t usually take estimates of the cost of bad diets and obesity too seriously because they are necessarily based on multiple assumptions, none of them verifiable.  But I do like to collect them.  Here are two papers from the American Journal of Health Promotion estimating such costs.  One estimates the health benefits and savings in medical costs from diets reduced in saturated fat, sodium, and calories (a savings of $60-120 billion), and the other estimates cost savings and productivity increases for reduction in calories and sodium ($109-256 billion).  Whatever the real savings are, they are likely to be enormous.  And that’s just money.  It’s harder to put a value on quality of life.  Maybe that’s all we need to know at this point.

Yale’s Rudd Center for Food Policy has invented a Revenue Calculator for Soft Drink Taxes for estimating the amounts of money states and cities could raise from taxes on soft drinks.  You type in the state or city, estimate the size of the tax, decide what kinds of drinks it’s for, and push the  button.  Bingo.  California could raise about $1.8 billion a year from a 1 cent tax.

And the Department of Health and Human Service has hooked up with the Advertising Council for a new kids’ activity campaign on the Internet, this one using Maurice Sendak’s Wild Things tied in to a movie coming out in October.  I wasn’t so happy about the last such campaign, which featured Shrek and is still up on the site.  Shrek also advertises junk foods.  Maybe this one will work better?

Aug 5 2009

What We Eat in America: Latest Info

I’ve long argued that finding out what people eat is the most intellectually challenging aspect of nutrition research.  To put it bluntly, everybody lies. OK.  We don’t lie.  We just can’t remember or estimate portion sizes accurately.  For years, government agencies have gone to great trouble and done the best they can to get some reasonable idea of what Americans actually eat.  They report the results as “What We Eat in America.”  The data may not be perfect (they almost certainly underestimate actual intake), but they are the best we have and always of great interest.

I always like to know what is going on with calories.  The USDA’s most recent data are from 2005-2006.  These show that women on average consume 1785 calories a day, men 2638, and together 2157.  These figures are based on intake reported for 24 hours and almost certainly underestimate real calorie intake by one-third or more.  Compare these figures to calorie production, which is now 4000 per capita per day! (See Table 1).   The truth undoubtedly lies somewhere in between and all we can do is make good guesses.

USDA files its dietary intake reports under Products & Services.   Its latest looks at intake of four nutrients: calcium, vitamin D, phosphorus, and magnesium.  In comparison to dietary reference intakes (DRIs), Americans eat pretty well.  The low magnesium intake makes me wonder if the  DRI for that nutrient is too high, but I tend to be skeptical about such things.

Everything about these reports requires much careful interpretation, since every element of obtaining dietary intake information is fraught with error.   Better methods would help a lot.  If only we could figure out how to do this better.  A challenge, indeed.

May 19 2009

Eating well on a low budget?

Adam Drewnowski and his colleagues at the University of Washington have been doing a series of papers on the cost of food per calorie.  The latest is a research brief answering the question, “Can low-income Americans afford a healthy diet?”  Not really, they say.  Federal food assistance assumes that low-income people spend 30% of their income on food but that assumption was based on figures from an era when housing, transportation, and health care costs were much less.  As Drewnowski has shown repeatedly, healthier foods cost more, and sometimes a lot more, when you look at them on a per-calorie basis.

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