The Best Diet is the One You’ll Follow
The only sure-fire way to lose weight is taking in fewer calories than you burn.
Psst. Want to know the secret to losing weight that diet books have been hiding from you? Take in fewer calories—it doesn’t really matter how, according to a new study—and get some support for your efforts.
For years, we’ve been told that fiddling with the form of calories is the way to lose weight. First came low-fat diets, like the American Heart Association Step I diet or the Ornish diet. They were pushed aside by low-carb diets like the Atkins and South Beach diets. Higher-protein approaches, like the Zone diet, had their day on stage,along with everything in between, from Sugar Busters! (eat no sugar) to the Paleo Diet (eat like a cave man).
The conclusion from the latest head-to-head trial comparing different weight loss strategies, however, is that what you eat takes a backseat to how much you eat. What really matters for weight loss is that you take in fewer calories than you burn. How you get there is immaterial, according to the study, which was published in the February 26, 2009 New England Journal of Medicine. (1)
Researchers from the Harvard School of Public Health, Harvard-affiliated Brigham and Women’s Hospital, and Louisiana State University’s Pennington Biomedical Research Center compared the effect of four different diets on weight loss. They recruited more than 800 motivated volunteers. Each one was randomly assigned to one of four prespecified diets that were loosely based on popular diets like Atkins,Ornish, and the Mediterranean diet: low fat, average protein; low fat, high protein; high fat, average protein; high fat, high protein (see table, Overview of Weight Loss Diets and Results). Each of the diets met the American Heart Association’s recommendations for cardiovascular health. Each plan cut about 750 calories from a participant’s normal daily diet; no one ate fewer than 1,200 calories a day.
The participants were given daily meal plans, were asked to attend weekly support sessions, and were encouraged to exercise at least 90 minutes a week. Body weight, waist circumference, cholesterol levels,and other measures were gathered at 6 months, 12 months, and 2 years.
Over the first 6 months, the participants lost an average of about 12 pounds and had a 2-inch drop in waist size, regardless of the diets they were following. At 12 months, most began to regain some weight. At2 years, the amount of weight lost was similar across the four plans, on the order of 7 to 9 pounds (see table, Overview of Weight Loss Diets and Results). Feelings of hunger, of being satisfied(satiety), and of satisfaction with the diet were the same across the board. So were cholesterol levels and other markers of cardiovascular risk.
The averages, though, hide the huge variation in weight loss seen in this and other diet trials, pointed out lead researcher Frank Sacks, M.D., professor of cardiovascular disease prevention in the Department of Nutrition at Harvard School of Public Health. Some of the participants lost 30 pounds or more on their diets, while others actually gained weight during the trial. The study also found that the more group counseling sessions participants attended, the more weight they lost, and the less weight they regained. This supports the idea that behavioral, psychological, and social factors are probably far more important for weight loss than the mix of nutrients in a diet.
This study joins a handful of trials that have shown that low-carb and low-fat diets both work in the long run, as does the Mediterranean diet. (2-6) Some of the earlier trials suggested that the low carb approach yielded somewhat faster weight loss, but this latest trial did not find any speed advantage for one diet over another.
How to Put These Diets into Practice
The take-home message from this trial and other recent weight loss trials is simple: If you are serious about losing weight, find a diet that appeals to your taste buds. If it’s one your family can follow, so much the better—that way you aren’t making different meals for you and your family.
The form of the calories you take in matters for only one reason: helping you stick with the diet. If you prefer protein, then a higher-protein diet might help you lose weight better than a diet that emphasizes carbohydrates. If you like variety and vegetables, try a Mediterranean approach. If you believe that eating fat makes you fat (it doesn’t, anymore than eating protein or carbohydrate makes you fat), then try a low-fat approach like one of the Ornish plans.
Better yet, build your own plan. It should provide plenty of choices, have few restrictions, and be as good for your heart, bones,and brain as it is for your waistline. It should be a diet you are excited about trying, or at least not dreading. Most important, it should deliver fewer calories than you usually take in.
What’s the best way to determine that? If you can see a nutritionist, she or he can help you figure out how many calories you usually consume. The process usually involves keeping a diary or record of everything you eat, drink, and nibble on over the course of three days. This can be converted to calorie counts and your daily caloric intake. You can also do this yourself online, suggests study co-author Kathy McManus, R.D., director of the nutrition department at Brigham and Women’s Hospital. Many web sites offer online food diaries that automatically calculate your calorie intake. Some you have to pay for, others offer up ads for diet products. A free, and ad-free,site worth trying is MyPyramidTracker, set up by the U.S. Department of Agriculture to support its new food pyramid. The site also has an exercise tracker.
Once you know how many calories you take in on an average day, you can set a target for the future. A 500 calorie deficit is a good place to start. Do that for a week, and you’ll lose a pound of fat (which is the equivalent of 3,500 calories). You can adjust your diet to take in 500fewer calories a day. Or you can cut back by 250 calories (the amount of calories in a 20-oz bottle of sugary soda pop, a 16-ounce vanilla latte, or a jelly donut) and exercise long enough to burn an extra 250 calories (walk an extra 2 miles, take 5,000 more steps, swim for an extra 20 minutes, or do whatever exercise you prefer).
This kind of plan doesn’t have a catchy name. But it has something better—a proven record of success.
|Diet composition|| Percent
| Weight loss at
|Low fat, average protein||20||15||65||6.6 pounds|
|Low fat, high protein||20||25||55||8.8 pounds|
|High fat, average protein||40||15||45||7.0 pounds|
|High fat, high protein||40||25||35||7.5 pounds|
1. SacksFM, Bray GA, Carey VJ, et al. Comparison of Weight-Loss Diets with DifferentCompositions of Fat, Protein, and Carbohydrates. N Engl J Med. 2009; 360:859-873.
2. GardnerCD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, andLEARN diets for change in weight and related risk factors among overweightpremenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA. 2007; 297:969-77.
3. BrehmBJ, Seeley RJ, Daniels SR, D’Alessio DA. A randomized trial comparing a verylow carbohydrate diet and a calorie-restricted low fat diet on body weight andcardiovascular risk factors in healthy women. J Clin Endocrinol Metab. 2003; 88:1617-23.
4. FosterGD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet forobesity. N Engl J Med. 2003;348:2082-90.
5. DansingerML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ. Comparison of the Atkins,Ornish, Weight Watchers, and Zone diets for weight loss and heart disease riskreduction: a randomized trial. JAMA.2005; 293:43-53.
6. ShaiI, Schwarzfuchs D, Henkin Y, et al. Weight Loss with a Low-Carbohydrate,Mediterranean, or Low-Fat Diet. N Engl JMed. 2008; 359:229-241.
The aim of the Harvard School of Public Health Nutrition Source is to provide timely information on diet and nutrition for clinicians, allied health professionals, and the public. The contents of this Web site are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Web site. The information does not mention brand names, nor does it endorse any particular products.