HCG, or Human Chorionic Gonadotropin, is a hormone produced during pregnancy by the placenta after implantation, and doctors sometimes prescribe it for fertility issues. But this hormone has also gained popularity as a weight-loss supplement — and using it as such can be dangerous. In fact, the U.S. Food and Drug Administration (FDA) warns against purchasing over-the-counter hCG, as these supplement products are illegal. (34)
This popular diet program is fairly restrictive — and for the first 30 days, dieters must cut out grains, legumes, most dairy, added sugar, and alcohol without any slip-ups, according to the Whole30 website. (29) The aim is to “reset” your body and to adopt dietary habits resulting in weight loss. Cutting out added sugar and alcohol has merit, but all the restrictions prove challenging and could lead to nutrient deficiencies and disordered eating.
Skimp on fluids, and your body will release an antidiuretic hormone that leads to water retention that could affect the scale, Dr. Setlzer says. While this sneaky effect is one reason why the scale is a poor measure of body mass loss, you can outsmart it by drinking more—particularly if you fill your glass with water or non-calorie alternatives like unsweetened coffee and tea.
Consequently, researchers have widely discredited the hCG diet, which involves using hCG injections, pellets, sprays, or drops, and consuming as few as 500 calories daily. The diet is problematic not only because there’s a lack of research on hCG supplements, but also because the calorie requirement is dangerously low, potentially leading to nutrient deficiencies, fatigue, hormone imbalances, blood clots, and other issues. Thus, most experts agree the hCG diet is not safe for anyone, the Mayo Clinic notes. (35)
If you’ve been eating fast food for years, get real about your approach: You’re probably not going to stick to an organic, gluten-free, paleo overhaul for very long. "You want to change as little as possible to create calorie deficit," says Dr. Seltzer, who insists the best way to support sustainable weight loss is to incorporate small changes into existing habits. So instead of giving up your daily BLT bagels in favor of an egg-white wrap, try ordering your sandwich on a lighter English muffin. Or say you eat a snack bar every afternoon: Swap your 300-calorie bar for a 150-calorie alternative. "Your brain will feel the same way about it, so you won’t feel deprived," he says.