by Marion Nestle
Jan 31 2012

Want to lose weight? Eat less.

A new diet study just out from the American Journal of Clinical Nutrition went to a lot of trouble to prove the obvious.  When it comes to weight loss, how much you eat matters more than the proportion of fat, carbohydrate, and protein in your foods.

Researchers at the Pennington Biomedical Research Center got volunteers to eat diets that were supposed to differ in proportions of fat (40% vs 20%), carbohydrates (35% vs. 65%), and protein (25% vs. 15%).

The results of the study are consistent with the findings from many previous studies:

  • The major predictor for weight loss was adherence to the diet.
  • People on all of the diets lost weight by six months, but regained some of it by two years.
  • The study had a high drop-out rate (hence the importance of adherence).
  • It was hard for people to stick to the diets, especially those at the extremes of one dietary component or another.

In my book with Malden Nesheim coming out on April 1, Why Calories Count: From Science to Politics, we review the previous studies of whether what you eat matters more to weight loss than how much you eat.

Some people find it easier to stick to diets that are higher in protein and fat.  I’m guessing that proponents of low-carbohydrate diets will argue that none of the diets in this particular study was really low in carbohydrate.

But studies show that people have a hard time adhering to diets that are very low in carbohydrate.  The low range in this study—35%—is at the lower end of acceptability for many people.

The bottom line: all diets work if you stick to them.

  • Great post! I’m excited to read your upcoming book. The biggest sham of the diet industry is that it has convinced Americans is that “you should never feel hungry.” But, shouldn’t one always feel hungry before eating a meal? We have a very imbalanced understanding of what it means to feel “hungry” in the U.S. especially because of the denotation of the word (“poor,” “denying oneself”). The diet/weight loss industry wants to sell meal plans, pills, snacks, drinks. It’s encouraging, at least, to see more public ad campaigns that take on diet in terms of health rather than weight loss. But I would like to see a better understanding of what it means to be “hungry” and “full.” I think that’s part of the reason people don’t stick to their diets. They misunderstand the natural cycle of feeling hungry.

  • Marion,

    No doubt, you are one of my “health heroes”. You provide great advice backed by a tremendous amount of research.

    But …

    The advice to Eat Less is a misdirection. Of course, most experts tell us to eat less. When I think of eating less, two words come to mind … willpower and deprivation.

    Most people who have figured out the weight loss issue will agree with one of my health advocate friends … “If I’m hungry, I eat, and I don’t think twice about calories.”

    Carbs and fat are a misdirection … I’d rather replace them with these two “magic” words … Satiety and Taste (identify foods with health benefits that taste great). Once the satiety and taste equation is understood, all the other issues fall by the wayside.

    Here’s another one of my “health heroes” who explains …

    I am looking forward to your new book.

    Kindest regards,

    Ken Leebow

  • Andrew

    Have you had the opportunity to read Gary Taubes’ book “Why We Get Fa: And What to Do About It”? I just finished reading it and will be using it as a basis to counsel two individuals on weight loss this coming Thursday. He implicates carbohydrates as the cause of the diabetes and obesity epidemic and that curtailing carb intake – he mentions intakes as low as 20 grams per meal – and moving to a high-fat, low-carb diet will have beneficial effects on both weight loss and cardiovascular disease markers, such as a reduction in triglyceride and elevation in HDL levels. It’s not much different from the claims that the Paleo Diet proponents are making, eating what our hunter-gatherer ancestors ate.

  • I think it’s more important to eat nutrient dense foods…Just telling people to eat less without giving them the proper way to satisfy the bodies needs is kinda cruel.

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  • ETAddison

    Help me here. How does this prove that diets work?

    Clearly, telling/counseling/cajoling people into ‘eat less’ does NOT turn obese people into lean people. Two years of trying to eat less, and they are not lean.

    To quote the study authors. “Dietary goals were not met.”

    This mirrors the results of many, many, studies.

    Yet the call, as always is, ‘let’s try it again, only harder.’

    Or, the implication becomes that ‘obesity’ is a personality disorder, a psychological problem. People are too weak-willed to eat less.

    In which case, why are ‘nutritionists’ trying to solve a psychological problem?

    Somebody is missing something somewhere.

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  • Tyler

    Why is there no mention of the physiological differences of hormonal signalling found between different macronutrients?

    Some sources of calories are more satiating than others. It’s true that if you restrict calories on non-metabolically broken individuals, they will lose weight. But some foods will leave you more full than others if you eat the same amount of calories.

    And then there’s the whole concept of food reward/palatability. A recent post on a clinical review paper by an author:

  • Margeretrc

    It’s impossible to draw any meaningful conclusions from this study–the subjects had a hard time sticking to the diets (“Dietary goals were not fully met; self-reported contrasts were closer to 2% protein, 8% fat, and 14% carbohydrate at 6 mo and 1%, 7%, and 10%, respectively, at 2 y.”)
    You say “studies show that people have a hard time adhering to diets that are very low in carbohydrate.” What studies? I love it when people throw out a statement like that and don’t provide any back up in the form of actual studies. I can just easily say that “studies show that a very low carbohydrate diet is at least as easy to stick to as a low fat, low calorie diet.”
    For most people, myself included, low carbohydrate is not a diet, it’s a lifestyle, and it is not difficult to stick to at all, because there is no restriction on calories, fat or protein–and no need to go hungry. If a low carbohydrate diet is difficult to stick to, I’d be willing to bet that it also restricts fat and yes, that would indeed be difficult to stick to, not to mention dangerous. I’m in regular contact with many, many that have stuck to a low carbohydrate lifestyle for 10 or even 12 years. I regularly eat a maximum 15% of my calories as carbohydrates (assuming I take in about 1500 calories, but I don’t count calories so I have no idea and I probably take in much more), lower than any of the values in the study above and lower than the 35% claimed to be “lower end of acceptability for many people.” And I know many, many people who eat even less carbohydrates. The blogosphere is chock full of sites maintained by and visited by people who follow a lifestyle wherein they consume much less than 35% of their calories in carbohydrates. Because you are right, even 35% is a fairly high percent of calories from carbohydrate–only 10% less than the lower end of the USDA recommendations. Do I follow a low carbohydrate lifestyle because I am overweight or obese and need to lose weight? Actually, no. My weight and body composition are actually pretty health for my age. I follow it because, after reading Gary Taubes and others, I believe that it is far healthier than any other lifestyle. Certainly healthier–and easier–than the low fat, high carb lifestyle I used to follow and gained weight on. I am my own control. I have followed both low fat and low carbohydrate diets and have gotten much better results with the latter. Perhaps I’m unique, but I highly doubt it–and in fact know I’m not. I know (of) a lot of people like me. One of them even made a documentary, “Fat Head.” It’s a great watch.

  • Benboom

    I was going to answer this post but Margeretrc already said it all. But she said the evil word “Taubes”, LOL! I can’t speak for other people but I haven’t had any trouble staying on a low carb diet (with lots of good fat in it) and it was certainly much easier for me to lose weight on it than it was when I tried simple calorie restriction (“eating less”). What I notice is that when I say things like this, though, is that the usual response is “So what? You’re an exception.” 🙁 Fine, let’s throw out the scientific method altogether then, because of exceptions.

  • justthefacts

    I despair.

    Your wise words continue to fall on deaf ears. The message is missed in favor of journalistic opinion.

    Just for balance, I offer MY anecdote: Lost 45 lbs. Kept off for six years now. News Flash–cut my calories almost in half. Balanced diet from all food groups emphasizing veggies and fruit. Very low fat. Made it a lifestyle. Hungry sometimes? Yes. Starving? No. Jill Duffy has the right idea here. Marketers have convinced us that we “deserve” food and “treats” all the time and have made sure it is readily available on every corner. As Marion has noted numerous times, we have twice the number of calories available now as thirty or so years ago–more carbs, more fats–more CALORIES.

    If anyone is happy eating little or no carbs and can lose (and maintain) weight–well, goody, but you are reducing your calories at the same time or you would not be losing weight. Hopefully you all will take a look at the new book when it arrives and acknowledge that Marion has much better credentials than Taubes

    For the umpteenth time, paleolithic people did not eat meat all the time. They subsisted primarily on roots, berries and small amounts of nuts. Meat was a now and then feast when the hunt succeeded.

  • People are missing the point here. Saying that “people can’t stick to diets so they don’t work” is faulty logic. Anything is going to fail without willpower. Eating less calories is not hard if you keep track of your food intake, and it encourages healthier eating simply because vegetables and other healthier fare becomes a ‘free food.’ A whole pot of cauliflower is like 30 calories. It’s the same reason that so many people swear by Weight Watchers, although that uses points instead of kcals.;

  • This argument will run, and run.

    We started this discussion in the 1950s, took it up a notch in the 1960s, forgot about it in the 1970s, and then corn sugar or HFCS raised the temperature again in the 1980s.

    Since the 1990s, we have been arguing over the type of diet, type of exercise, if it is diet and exercise and all the while waistlines have been expanding around the globe.

    There hasn’t been one dieting stone left unexplored. Yet globally there are just as many, if not more, people overweight and obese as those starving.

    Could it be that the ultimate causation is not the diet, but the calories and why human behavior is programmed to eat so many of them? Could it be that food marketing has stumbled upon a human flaw and they just keep exploiting it, provoking it and sustaining it?

    Think about the concept of ultimate causation. It could be a really big white elephant in the kitchen.

  • Roxanne

    I recently found out I’m gluten intolerant, so 3 weeks ago I cut out ALL grains out of my diet and adopted a Primal Blueprint lifestyle (google Mark Sisson or visit I feel SO MUCH BETTER. My carb count is from 50-100 grams/day (just enough to burn fat but keep me out full-blown ketosis–no need for ketone breath!). I get plenty of carbs with veggies, fruit, a bit of dairy, nuts, and seeds.

    On a high carb diet (w/ grains, such a diet is as high as 400g/day!), I was CONSTANTLY hungry. All damn day. It was crazy. There is a major difference between acknowledging hunger when it’s TRUE hunger and being constantly plagued with toxic hunger because you have insulin running around your body all day long.

    On Primal Blueprint I am finally free from toxic hunger (you MUST eat now or you will faint!), which would occur every 3-4 hours, and can truly wait until I feel REAL hunger to eat. And if at that point during my day I find that I don’t yet have time to eat, I can wait patiently until I have time to really eat real food. I can go up to 12 hours now before I really need to eat.

    It’s so freeing not to be shackled by constant blood sugar swings from a high carb diet. This is an eating plan I can really stick to because it makes me feel so damn good. It’s healthy and right for me (and I’m already starting to see weight loss), and that should be the whole point to any eating style!


    I’m also following GAPS (almost identical to Primal Blueprint, with the addition of homemade bone broths and fermented foods) to heal my digestive system from years of gluten abuse.

  • Margeretrc

    Can a person lose weight by simply eating less across the board? Of course–that is if your metabolism isn’t broken/you don’t have too much to lose. Can one sustain that way of eating and keep the weight off? Well, maybe if you are @justthefacts, but…Here is a discussion of how successful reducing calories/fat is (not) in taking weight off and keeping it off for most people and why. And here is a logical answer:, a letter signed by more than 250 medical professionals and researchers who apparently, despite his lack of qualifications, agree with Gary Taubes.
    @justthefacts, “…you are reducing your calories at the same time or you would not be losing weight.” True. Some. But it’s so much easier to eat fewer calories when you are not hungry! And there’s this thing called Metabolic advantage. Here’s an explanation: Dr. Feinman is Professor of Biochemistry at Downstate Medical Center (SUNY) in New York. You can check his qualifications here:
    @edSanDiego, “Could it be that food marketing has stumbled upon a human flaw and they just keep exploiting it, provoking it and sustaining it?” Kind of. The government, based on some rather flimsy science, told us to reduce our fat intake and the food manufacturers were only too happy to help by supplying us with reams of “low fat” or “no fat” products (I hesitate to use the word food) which people are only too happy to consume and they figure they can eat as much as they want because it’s low or no fat. If you remove the fat, you have to add something to make it palatable: sugar! Draw your own conclusions.

  • Peggy Holloway

    Low-calorie, low-fat for most of my adult life (started dieting at age 13). By age 40, I had major health issues and by 45, could no longer manage my weight even on a near starvation diet with lots of exercise. My blood sugar/insulin swings were nearly debilitating. I switched to a very low-carb lifestyle in January of 2000, and after 12 years, I would never eat any other way. My health is great, I eat satisfying foods, and never count calories (or carbs for that matter – I just don’t eat starch, grains, or sugar and don’t worry about numbers). To claim that cutting calories “works” is to ignore the role of insulin in metabolism (as many others have commented) As Gary Taubes points out, if eating less does work for weight loss, it is because by cutting calories, you also will cut your carb intake enough to improve insulin response.
    I know a vast number of people, including nearly my entire family, who have had no success with the concept of cutting calories and increasing exercise but do very well with a low-carb lifestyle. The benefits include the eradication of mood swings, chronic fatigue, ADHD, insomnia, eating disorders – and most important of all: my family is very insulin-resistant and my father and grandfather died with complications of “type ii diabetes.” My siblings and children are avoiding that fate with a low-carb lifestyle. I have had completely normal fasting blood sugar ever since adopting the low-carb lifestyle and believe fervently that this is the only way to keep blood sugar/insulin normal in people with my genetic make-up.

  • Beth@WeightMaven

    Marion writes: “The bottom line: all diets work if you stick to them.”

    So the raise in the rate of obesity is due largely to a global failure of personal responsibility? Sigh.

    Calories do count, but there’s more to the story!

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  • The interesting point is that the number 1 predictor of losing weight is an “adherence to the diet.” From a Public Health perspective, diet’s just don’t work. The focus on the individual needs to be moved further upstream if any behavior change will occur.
    Interventions that focus on the individual’s values as a starting point then implementing programs that are beyond their control will result in much better outcomes than to solely focus on educating people. One of our innate desires is to eat, now we need to find what benefits people can receive, or what the cost is that they will give up in order to help them adhere to these diets.

    The fad diets just aren’t working! We need to ask ourselves questions as health educators/promoters, what do people value in connection with how they eat? Once we figure this out, we will be on our way to changing behavior for the long haul.

  • “Eat Less,” now that’s the spirit, we have seen how effective that has been in history.
    If I recall, the meat and milk industry is heavily-lobbied, and have massive amounts of money to fight against anything that says eat less of their products. For example, in your book Food Politics it mentions this long and continuous battle against eating less. The USDA and the food guide pyramid in the early 90’s encountered many problems with trying to use this phrase, “eat less.” As a result, the USDA gave into the pressures of these powerful industries and the food guide pyramid represented a misrepresentation of the amounts of certain foods we need on a daily basis.
    People don’t like “eat less,” it instills a sense of starvation, deprivation, and these are words that we don’t want associated with changing behavior. We need to make the right behaviors pleasurable and the wrong one’s painful, not the other way around.

  • losingitin2012
  • Hylton

    Marion Nestle wrote:
    “Want to lose weight? Eat less.”

    “A new diet study just out from the American Journal of Clinical Nutrition went to a lot of trouble to prove the obvious.”


    Marion Nestle wrote:
    “The bottom line: all diets work if you stick to them.”

    Certain diets are more demanding on the environment and take no account of any expanded concern for ethics. You don’t have to be an animal rights activist to comprehend that factory-farming of animals is abhorrent.

    It’s 2012. There is more to diet than weight loss and even health. If all diets are more or less the same on these fronts, it’s way past time to consider other criteria to shape collective food choices.

    There’s more than enough data suggesting what type of diet is a poor environmental choice for a civilization to adopt. Perhaps not coincidentally, a pattern of eating that is environmentally preferable is also one that is high in whole grains, vegetables, and fruits.

    This blog is called Food Politics, so topics beyond weight loss and health should be open for discussion.

  • ICDogg

    What a crapload.

    I have lost 70 lbs. in the last 6 months not eating any less (or less calories for that matter) than I was before, and not with a lot of exercise either.

    I have been far more successful at doing so, and having a pretty easy time of it, than I ever did with any of this B.S. advice about eating less.

    It’s the sugar. It’s the grains. It’s the starches. That’s what make us fat, and that’s what we have to cut out to make us thinner. And that includes the whole grains and sugary fruits that we’ve been led to believe are so healthy.

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  • Jo Marsette

    I was overweight and tried so many things. Different things work for different people and I was lucky enough to find one that worked for me. I lost 22 pounds in one month without any exercise and it’s been a life changer. I’m a little embarrased to post my before and after photos here but if anyone actually cares to hear what I’ve been doing then I’d be happy to help in any way. Just shoot me an email at and I’ll show you my before and after photos, and tell you about how things are going for me with the stuff I’ve tried. I wish someone would have helped me out when I was struggling to find a solution so if I can help you then it would make my day

  • ICDogg

    Btw the weight is still off.