A very low calorie diet is a sure-fire way of losing weight, and losing it quickly. After all, the body is consuming a fraction of the energy it requires. But once that weight is lost, will it stay off? Fat chance. (Pun intended).
Very-low calorie diets are unlikely (and really not favorable) for long-term use, being extreme in nature and generally lacking many essential nutrients. After reaching their goal weight, people typically return to old eating habits and ultimately regain all the weight loss and sometimes even more. According to scientists, the body has several defense mechanisms against weight loss, such as increased hunger, lower energy metabolism and relapse back to old habits.
So how can weight be maintained, once lost?
One review article, published online Oct 2013 from the Department of Medicine in Sweden found that there are several effective strategies for keeping weight loss off. The scientists reviewed a total of twenty, past clinical trials with over 3000 participants, that had used weight maintenance strategies after low and very low calorie dieting which resulted in significant weight loss.
The participants in all studies were either obese or overweight and strategies used after weight loss for weight maintenance included dietary supplements, exercise, high-protein diets, anti-obesity drugs and meal replacements. The participants who were able to successfully maintain weight loss were associated with using high-protein diets, drugs and meal replacements. No significant improvements were seen with those using dietary supplements or exercise.
Exercise surprisingly did not confer weight maintenance benefits, but it was stated (in the review) that this was perhaps due to lack of uniformity among the type of exercise used and health status of the subjects.
(Not surprisingly,) high-protein diets described as using 20-30% of energy intake, were successfully used for maintaining weight as protein is known to increase satiety, preserve muscle mass and burn energy during digestion.
Meal replacements were described as being nutrient dense but low in calorie.
Anti-obesity drugs in review included orlistat, sibutramine and topiramate which work through various mechanisms such as reducing appetite or reducing fat absorption.
While all three of these methods are effective, the drugs must be prescribed and always carry risk of adverse event, whereas high protein dieting and meal replacements are safe and available to everyone.
By: Scarlett Full, in-house Registered Dietitian
Reference: Johansson et al. Effects of anti-obesity drugs, diet, and exercise on weight-loss maintenance after a very-low-calorie diet or low-calorie diet: A systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr. Jan 2014. doi: 10.3945/ajcn.113.070052