The key to long-term weight loss and maintenance might be to lose weight quickly rather than gradually, at least in the initial stages of dieting, a new study suggests.
More research is needed to determine the best approach, however.
Successful weight loss in obese individuals is defined as a reduction of 10 percent or more of initial body weight maintained for at least a year. The jury is still out, however, as to whether fast or slow initial weight loss is the best approach for weight control over the long-term.
On the one hand, there is evidence that starting off a diet losing weight slowly results in continued weight loss, reduced risk of weight gain later, and successful long-term weight loss maintenance. On the other hand, it has also been shown that the greater the initial weight loss in obese people, the larger the total weight loss observed longer-term.
The new study, conducted by Lisa Nackers and colleagues, from the University of Florida, looked at data from 262 middle-aged obese women who took part in a six-month weight loss program.
Participants were encouraged to reduce calorie intake and increase physical activity to achieve an average weight loss of just under a pound (0.45 kilograms) per week for the first six months. Then during the following year, participants got weight-loss support that involved contact twice a month in the form of group sessions, telephone contact or newsletters.
The researchers found that some of the women shed pounds quickly, while others did so relatively gradually, and others were slow to lose weight during the first month of the study.
Women in the fast weight-loss group lost over 1.5 pounds (0.68 kg) per week; those in the moderate group lost between 0.5 and 1.5 pounds (0.23 and 0.68 kg) per week; women in the slow group lost less than 0.5 pounds (0.23 kg) per week. They then looked at the women’s weight loss at six and 18 months, as well as any weight regain at the end of the follow-up year.
Those in the fast weight-loss group shed more weight overall, maintained their weight loss for longer and were not more likely to put weight back on than the more gradual weight losers. At the end of six months, women in the fast group lost an average of around 30 pounds (13.5 kg), while those in the moderate group lost around 20 (8.9 kg), and those in the slow group lost about 11 pounds (5.1 kg).
Women in the fast group were five times more likely to achieve the clinically significant 10-percent weight loss at 18 months than those in the slow group. And those in the moderate group were nearly three times more likely to achieve this milestone than women in the slow group.
"Our study provides further evidence that, within the context of lifestyle treatment, losing weight at a fast initial rate leads to greater short-term weight reductions, does not result in increased susceptibility to weight regain, and is associated with larger weight losses and overall long-term success in weight management," the authors write in the International Journal of Behavioral Medicine.
The researchers suggest that weight-loss programs should promote " large rather than small behavioral changes during the initial weeks of treatment."
However, past research has shown that rapid weight loss right off the bat, like that which occurs on the TV show "The Biggest Loser," can be hazardous to a person's health.
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