A Diet for Keeping the Weight Off?

Losing weight for the overweight and obese individual is hard task, and yet it’s almost inevitable that many successful losers will regain their lost pounds in subsequent months.  Achieving body weight maintenance, or try to, was the subject of a large European study reported recently in the New England Journal of Medicine.    

Overweight adults from 8 European countries who had lost at least 8% of their initial body weight using a restricted calorie diet were enrolled.  They were to undergo a 26-week period eating one of 5 diets ad libitum; the diets contained varying amounts of protein and low-glycemic-index (low-GI) items, aimed at preventing weight regain.  (The glycemic index reflects the effects of foods on postprandial blood glucose levels; low-glycemic-index foods raise the blood sugar relatively less.)  Fiber and fat levels were similar in all 5 diets.  The five diets were:

a control diet

low-protein/low-GI diet

low-protein/high-GI diet

high-protein/low-GI diet

high-protein/high-GI diet

A total of 773 participants were randomized to one or other diets; 548 completed the maintenance phase.  Fewer participants in the two high-protein groups and the low-GI group dropped out than those in the low-protein/high-GI group: 26% and 25%, vs. 37%, respectively.  Those in the high protein groups were almost twice as likely to continue losing weight – an additional 5% of their body weight.

By the end of the 26 weeks, weight regain was an average of 2.09 pounds less in the participants in the high-protein than those in the low-protein diet groups.  Weight regain was also less, by 2.05 pounds, in those in the two low-GI groups.

There was another unexpected finding with this study.  Members of participants’ families often ate the same type of food as the actual participant – again with no restrictions on quantity. In those families where the participant was taking the high-protein/low-GI diet, the percentage of overweight/obese children actually fell during the study.       

The investigators of the study report that: “These findings indicate clearly that a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss.”  It remains to be seen what types of protein are important for a high-protein diet – animal or vegetable.  However, for people anxious to maintain their new weight, high-protein/low-GI is a clearly better way to go.