“The alkaline diet often has a focus on eating lots of fresh produce and unprocessed foods, which could be a good thing,” says Hultin. “However, keep in mind that this is not an evidence-based therapeutic diet. When people take it too far — for instance, drinking baking soda — or become too restrictive or obsessive over food choices, it can definitely turn negative.”
The fad military diet consists of low-calorie, odd food pairings such as bun-less hot dogs with banana, carrots, and broccoli. “Any diet like the military diet that severely limits the amount of calories you consume or eliminates one or more entire food groups puts any individual at risk for nutrient deficiencies,” says Kyle. “This can be more harmful than holding onto those 10 extra lb you’re trying to lose.” (32)
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.
The plan promotes long-lasting, sustainable changes, and undoubtedly a bounty of research backs this up. In fact, one December 2013 study in the American Journal of Medicine shows that people following Weight Watchers were close to nine times more likely to lose 10 percent of their body weight, compared to people following a self-help diet plan. (20)
“A lot of people think the foundation of a paleo diet is high-fat meat, but I suggest that it’s vegetables,” says Hultin. The concept is to eat only foods — including meat, fish, poultry, eggs, fruits, and vegetables — that would have been available to our Paleolithic ancestors. This means grains, dairy, legumes, added sugar, and salt are all no-no’s.
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)
Protein is also important for preserving muscle mass as you lose weight. If you cut back dramatically on calories and drop weight too fast, your muscles can suffer. Your body starts pulling from lean tissue like muscles and organs to fuel itself, and your metabolism slows to conserve energy. That’s why super restrictive diets that have you dropping weight fast aren’t healthy over the long run.
A relatively new offering, the Nutritarian diet is based on maximizing the amount of healthy vitamins, minerals, and trace nutrients in your food, balancing your hormones, and avoiding toxins. The plan—created by Joel Fuhrman, M.D., author of The End of Dieting—is nutrient-dense, plant-rich, and includes anti-cancer superfoods to help you not just lose weight but live a long, disease-free life. (P.S. Follow these guidelines to make sure you're absorbing all the nutrients from your food.)
If you like eating meat and want to lose weight, you might be tempted to try this recent extreme diet fad that proponents have made some pretty outrageous claims about. One: that eating nothing but meat can cure you of autoimmune diseases. The problem is that there’s no good research to support that notion, or any other health claim, for that matter. Indeed, omitting foods known to be good for you — fruits and veggies among them — can lead to a bunch of unwanted side effects, including constipation and potentially dangerous nutrient deficiencies. Still, since you’re cutting out so many food groups, there’s a decent chance you’ll lose weight, experts say. Regardless of any possible benefits you might see, this restrictive approach is definitely one you’ll want to ask your doc about before you even consider diving in.