Losing weight is a tough and frustrating endeavour. You have a goal weight or dress size in mind and are eager to get there, but it seems to take forever. Then, you see programs that promise to help you lose up to 20 pounds in a month, and that sounds intriguing — what could be wrong with hitting your goal weight in half the time? Turns out, not only are these diets too good to be true, they can do more harm than good.
Registered dietitian and ACSM-certified personal trainer Jim White, owner of Jim White Fitness and Nutrition Studios, said that while there are plenty of programs that make these lofty claims, it's not advisable. "As your body loses weight, there is a breakdown of both lean muscle and fat," he told POPSUGAR. "Unfortunately, lean muscle is lost before your fat stores."
Caroline Meehan, RDN, agrees. "Weight-loss plans that promote a weight loss of more than two pounds per week, or say 20-30 pounds in one month, tend to be unsafe, unrealistic, and unsustainable," she said.
Instead, Jim and Caroline both said a safe amount of weight to lose is one to two pounds a week. "If one is losing larger amounts of weight than that, it could indicate they are losing more lean muscle mass than fat," Jim said. "When your body loses its lean muscle mass, it will slow down your resting metabolic rate." As your resting metabolic rate drops, you burn fewer calories at rest. "This is why many dieters can lose some weight fairly easily, but then tend to plateau," he explained.
Instead of looking at the big picture and thinking you need to lose 30 or 40 pounds, Caroline advises setting smaller goals that promote sustainable weight loss. "Taking the focus off weight-loss goals and instead focusing on positive lifestyle changes that promote good health are the more important goals we should create for ourselves," she said.