Science Reveals How To Lose Weight And Keep It Off

Well, it was a long time coming.  Between the myriad of diet plans on television, magazines, online, and everywhere, someone was bound to finally come up with conclusive evidence on what works and how to make sense of all the (excuse the term) dietary diarrhea. No doubt, you've also noticed that low-fat, high fiber, extra protein, pills, germs, and steel floods every sensory organ we have on a hourly basis.

Personally, I've never been all that interested in skinny, but healthy suits me just fine.  I'm not one for regiments or counting calories, but do give thought to what I consume and prefer to walk or bike when possible--it benefits the heart, wallet, and environment. Weightwise, my take is that we humans have an interesting habit of coming in all shapes and sizes and the most beautiful tend not to fit a particular mold. That said, being healthy--inside and out--is everything. (After the past couple weeks, I can assure you of that).

But I digress... back to the original topic: science and weight loss

The latest edition of the New England Journal of Medicine features research out of the Harvard School of Public Health and the Pennington Biomedical Research Center.  Scientists monitored individuals for two years on one of four popular diets: low fat, high carb, high fat, and high protein. The results (drumroll please.....) i-3dc792e5b31abd917a2e97e63a9cd2b3-real women have curves.png

It's all about calories.

Go figure.

More like this

We need more women out there telling the same thing about beauty to our daughters!

Please specify that you're talking about dieting in normal, otherwise healthy overweight people, and not people with disorders such as diabetes.

By speedwell (not verified) on 26 Feb 2009 #permalink

Please specify that you're talking about dieting in normal, otherwise healthy overweight people, and not people with disorders such as diabetes. - speedwell

It's still all about calories/calories out. There are minor differences in the rate of calories out, but the rest is the 1st & 2nd LoT.

By natural cynic (not verified) on 26 Feb 2009 #permalink

This just cracks me up. I can't believe it took a fancy scientific study of years of data to determine fewer calorie intake leads to weight loss. That one is a no brainer!

Shelley, let's not Proxmire the story.

There is a multi-billion dollar industry based on telling people that weight loss is not a matter of calories in minus calories out. Given that, it's worth some study to see whether the various forms of sympathetic magic the fads invoke actually do have positive results.

Please note that this study only refers to short-term weight loss. All of the diets studied did "work," at least for a while. The study itself states, "We studied weight change over the course of 2 years, since weight loss typically is greatest 6 to 12 months after initiation of the diet, with steady regain of weight subsequently." Unfortunately, no one has really yet figured out how to maintain such weight loss over the long term.

Also, I'm always interested in noting that Dr. Greenway reports receiving consulting fees from or serving on a paid advisory board for Anian, Bristol-Myers Squibb, Clarus Health, Encore Pharmaceutical, Leptos Biomedical, MDRNA, Novo Nordisk, General Nutrition Corporation, Catalyst, Jenny Craig, Orexigen, Lithera, and Basic Research, receiving lecture fees from BAROnova, Lazard, and Biologene, and owning equity in Lithera. It may not mean a thing in this instance, but many weight loss studies do tend to be sponsored by groups such as these.

Unfortunately, no one has really yet figured out how to maintain such weight loss over the long term.


The way to "maintain" the lost weight is to continue to burn the proper amount of calories relative to the amount of calories you ingest. To lose weight, you need to burn more calories than you take in. To "maintain" you need to be sure you keep an equilibrium.

In other words, you must always exercise and eat right. It really is that simple. "Simple" being a relative term here. ;^}

But mk, why did the study participants start to regain weight despite the fact that they hadn't changed their routines -- eating fewer calories and burning more calories? They were still under the supervision of those running the study. Are you suggesting that they are cheating or just not working as hard as they had been?

See this graph, from the study:

Or perhaps you think that their metabolism has changed and now they need to start restricting their diets and exercising yet more. How long will that work? Will they have to continue restricting more and more over the long term?


This is a simple matter of physics. If you burn more calories than the calories you ingest you are going to lose weight.

I cannot speak for the study or it's participants. And it doesn't matter. Physics is what matters.

The only question I have regarding it's really all about calories 500 calories of broccoli less fattening than 500 calories of chocolate? Really....?

By darlenetait (not verified) on 26 Feb 2009 #permalink

Wow! If you can eat 500 calories of broccoli in one sitting... that'd be impressive! Gross! But impressive!


Why doesn't the study matter, when the study is what's being discussed?  That seems a bit useless.

That's without even getting into the part where a body is a complex machine, not a simple GIGO tube, so saying "burn more calories than you consume == win!" is incredibly simplistic.

Not "simplistic." Simple.

Conclusions: Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.

So . . . the scientist's conclusions don't match their data ("meaningful weight loss" only in the short term), but instead of taking the data, you're just going to use their apparently specious conclusion?

Way to be scientific!

"specious conclusion."

Now that's scientific! ;^}

Results: [...] By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) (P>0.20 for all comparisons). [...]

Conclusions: Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.

Uh... is no-one else seeing a placebo problem here? Without a control group who were on a non-reduced-calorie "diet", what is their justification for specifically referring to "reduced-calorie diets" in their conclusion?

Just going off the abstract (I'll read the actual paper on the train home) this appears to be a carefully-spun null result. Useful but not exactly "omg scientists grokz w8loss wtf".

1. Having the ring of truth or plausibility but actually fallacious: a specious argument.
2. Deceptively attractive."

A conclusion that sounds good and matches what we're told over and over but isn't supported by actual data . . . uh, yeah, that pretty much fits both the meanings of the word.

From the editorial: "Thus, even these highly motivated, intelligent participants who were coached by expert professionals could not achieve the weight losses needed to reverse the obesity epidemic." I know since you've read the study so closely, they eliminated everyone they believed to be "insufficiently motivated." So this is cream of the crop study participants, here.

From the actual study: "After 12 months, all groups, on average, slowly regained body weight." And this regain was on the same calorie deficit that they'd lost the original weight on. Which would be impossible - unless our bodies are complex and there are other factors involved. But it's more likely that we should just take the short term results of things and ignore the overall failure of diets to work for the large majority of people.

Also from the actual study: Only ~15% of participants had lost 10%+ of body weight at 2 years (and I'd *love* to see the numbers at five years, which is where pretty much every diet participant is back at or above their starting weight.)

Yes, I can see where this is rousing proof of the effectiveness of diets. Except where it's not.

What exactly does that clarify MK? Besides the fact that in that article they even admit it is nearly impossible to stick to a low calorie diet? Therefore... everone should somehow stick to a low calorie diet? Does that seem logical to you?

I will have to concur with Anita that the studies popularly touted conclusions are not valid based on the evidence they present. All of their groups began regaining weight only a year into the treatment. Perhaps if people only wanted to be thinner for 6 months this study would have some validity. Plus, 2 years is a very short time horizon for a medical study of this kind.

Well it's true that the flow of energy into and out of the body are the pathways for bodyweight regulation. I don't think any reasonable informed person argues that. If you treat the body as a black box, you only have what goes in, what goes out, and what is chemically converted from one form to another. But that doesn't neccessarily tell you enough by itself to be able to treat obesity.

The issues in obesity research assume that much and go farther. They attempt to find the specific mechanisms by which we maintain a stable bodyweight under most conditions, and how and why those mechanisms no longer maintain equillibrium when our bodyweight changes significantly.

If we regulated our intake or metabolic rate based on the proportion of macronutrients, then it would make sense that changing the proportion could result in weight change over time, it wouldn't be sympathetic magic. If it isn't true, that's a useful data point.

So fhe fact that total calories taken in matter more than the proportion of macronutrients is not a trivial piece of information. It tells us that if we want to alter our weight sustainably, we need to focus on calorie restriction rather than macronutrient proportion.

Then there are various strategies of different degrees of effectiveness for calorie restriction. By no means is it a foregone conclusion for example that just eating the same things in smaller portions would be a sustainable strategy. It does make sense to do this kind of research to verify how human beings really regulate their body weight. Obesity is not a trival problem to solve, and the research is making slow but real headway I think.

And y'know, I'm kindof surprised that a blog on a "science" site would re post a study without actually looking at how it was conducted and examining the science behind it. Isn't the whole point of science supposed to be questioning preconceived notions and looking for actual evidence?

But maybe that's not the point of this particular blog.

Are you suggesting that they are cheating or just not working as hard as they had been?

"Adherence, Diet Acceptability, Satiety, and Satisfaction

Mean reported intakes at 6 months and 2 years did not reach the target levels for macronutrients (Table 2). The reported intakes represented differences from target levels of fat, protein, and carbohydrate intake of 8.0, 4.2, and 14.4 percentage points, respectively, at 6 months and 6.7, 1.4, and 10.2 percentage points, respectively, at 2 years. Reported energy intakes and physical activity were similar among the diet groups. The participants who completed the study had a mean weight loss of 6.5 kg at 6 months, which corresponds to a reduction in daily energy intake of approximately 225 kcal."

So, yes they were unable to meet the goal and, as should be obvious, calorie in was, over time, greater than calorie out. So they regained weight. Why is this so hard for you?

Actually, all groups except one were eating fewer calories after 2 years than at the start. That one exception was eating on average 22 calories more per person after 2 years than at the start. So they DID stick with the program, and most of them were even eating less by the end. They still plateaued and eventually regained. Calorie restriction only leads to weight loss in the short term; in the long run, nothing statistically "works."

The body is not a bunsen burner. Biomechanics is very complex. It's actually very far from "simple."

Jason, I think that quote is actually misleading. To put it in plain english.

On average at 6 months the subject's caloric intake varied from target by 8.9%. On average at 2 years the subjects caloric intake varied from target by 6.1%. So at the two year mark subjects were actually closer to their target caloric intakes. I'm assuming that the caloric intakes were constant here, but that would indicate to me that at two years they regained weight while consuming fewer calories.

They were unable to meet targets, this is true. But they did reduce their overall caloric intake, and got closer to the targeted caloric intake over time.

I think it is also important to note that just because they did not reach target levels does not mean they did not reduce calories in below calories out. Without know thing the weights, heights activity levels and target caloric intake, we cannot make that assumption simply because they regained weight.

What we do know based on the aforementioned information is that a reduced caloric intake in this case did not cause sustained weight loss, and even though caloric intake was reduced further, subjects regained weight lost earlier in the study.

And considering the target was pretty severe - 750 calorie "shortage" based on original weight/activity - a 6-8% miss is neither surprising nor an indication that they were eating more than they were using.

Whatever you need to believe to get you through the night.


mk sez: "I can't hear you I can't hear you I can't hear you the human body works how I say it works!"

Denial seems to be working great for you, dear. Just go ahead and keep feeling superior, if that's what gets you through the night.

mk, I'm not sure what you're linking there. So a retired physics prof read the press release, and it reminded him of a diet plan from his university back in day. . . . yay?

I can send you a link to a prof's website that claims that there are aliens are amongst us, but that doesn't refute *actual* lack of evidence of aliens.

If you think the study is flawed, or you can find other studies that show long term weight loss, that would be worth discussion. Maybe you think it's a fluke, or that we're misinterpreting the data. But continuing to point to the press release and claiming it "proves" something is not constructive to the discussion, and misses the point of scientific studies completely - that the data is the important bit.

(insert passive-aggressive smiley here.)

The retired physics professor was reminded not of of a diet plan from his university from back in the day--clearly you didn't bother to check--he was reminded of his own "physics plan" for dieting: "burn more calories than you consume."

Ms. Kirshenbaum was clearly not the only scientist who read the report and saw that it confirms this particular "plan."

It is true that for some believing is seeing. For others, reality is more important.

I came upon this study because I am perplexed about my own weight loss. I can't seem to understand that after a year of working on my healthy eating, I finally, at the beginning of this year got into the habit of eating a set number of calories, about 1600 or less a day. The "or less" happens when I am just not hungry so I don't force myself to eat more than my body is asking for.

Additionally I have gotten up to 7 days a week working out. Again, not forcing myself. I started small but than I feel like working out so I do. Originally planned on taking the weekends off but I had too much energy and needed to run. So this morning I look at my scale and wonder why the hell it has not moved in 4 weeks. I am still at least 30lbs overweight. I have a spreadsheet showing everything I have consumed, drink plenty of water daily (I fill up a pitcher and drink it all during the work day and drink plenty more when i get home.) I get between 6-8 hrs of sleep. I am generally a happy person. So what's the deal? Oh, and my whole family is fat and most of them are diabetic except my sister and I.

My body fat percentage has not changed either so I can't even say muscle gain is the cause. My clothes fit the same. I just added running on the weekends to my routine so any plateau should have been broken from that.

Seriously, you can take my food spreadsheet and write a book on it and call it the next big diet. Nice balance of proteins, fiber, fat. Colorful vegetables and whole grains. I have gotten up to 25-30 grams of fiber and 80-90 grams of protein. Calories out is DEFINITELY greater than calories in. So what am I doing wrong?

Could it be true what everyone has been saying? Our bodies really are complex and its NOT that simple? Or am I lying about my routine? I really challenge anyone to tell me I am lying and in addition invite you to email me. Not to fight, but hopefully help you understand that maybe, just maybe, its NOT that simple for everyone.

By Patricia Garcia (not verified) on 11 Mar 2009 #permalink