Over the past two decades, diet crazes have flip-flopped from low calorie to low fat to low carb to high protein. Somewhere along the way, the high-fat “Mediterranean” style also gained popularity. So which of these conflicting concepts is the best for weight loss? There hasn’t been solid research to investigate the long-term results – until now. A recent study charted the progress of more than 800 subjects on 4 types of diets for two years.  We're breaking down the results.

Trying to lose weight is hard enough, but when the advice always seems to be changing, it’s enough for many folks to throw in the weight loss towel. Some of the main issues that send dieters reeling are:

• Conflicting information – one day it’s low carb, the next day it’s high fat...
• Nutrition advice comes from unreliable sources
• Some diets are incredibly hard to stick to
• Some diets only allow for short term weight loss -- what’s the point of losing weight if you can keep it off, right?!

There aren’t many reliable studies out there on the various types of diets. Many of the studies that have been done haven’t tracked progress for more than one year, which makes the long term effects hard to assess.

Some smaller studies have found that low carb “Atkins” type diets may yield a slightly faster initial weight loss over some of the other plans. But by the 12-month mark, the total amount of weight lost seems to be the same no matter which type of diet you follow. Dieters who’ve followed the low-carb style plans tend to complain of numerous adverse effects including fatigue and constipation (that doesn’t seem worth it to me).

Now, longer-term research is finally available. A study published in the New England Journal of Medicine followed 811 overweight men and women ages 30 to 70 were placed on reduced-calorie diets in 4 categories:

• Low-fat, average protein
• Low fat, high protein
• High-fat, average protein
• High-fat, high-protein (low carb)

In addition to their diet plans, the participants received nutrition education and instruction for 2 years.

After six months, all dieters averaged a loss of about 13 pounds and began to regain some of the weight after 12 months. At the end of 2 years, 80-percent of the participants completed the trial and the average weight loss was about 8 pounds per person. Attendance to the educational sessions was strongly associated with weight loss.

Bottom Line: It has been substantiated by research that a reduced calorie diet with continuing nutrition education is the way to go. Instead of worrying so much about low carb or high fat, try for a well-balanced diet with an appropriate calorie reduction for long term success.

Dana Angelo White, MS, RD, ATC, is a registered dietitian, certified athletic trainer and owner of Dana White Nutrition, Inc., which specializes in culinary and sports nutrition. See Dana's full bio »

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