If the diet is a quick fix rather than one that promotes lasting lifestyle changes, this could pose a problem. In particular, extreme diets that promise big weight loss up front aren’t always sustainable — and you may end up overeating or even binge eating if you feel deprived. “Consider if the diet’s habits are ones you can continue throughout your lifetime, not just 21 or 30 days,” says Angie Asche, RD, a sports dietitian in Lincoln, Nebraska.
The "all meat all the time" low-carb approach or strict veganism can be great options for people who thrive on clear diet rules (and those two are actually the most popular diets out there) but these extremes are not for everyone. If you prefer more of a moderate approach, the Flexitarian diet is the clear winner. The "flexible vegetarian" mindset allows you a healthy balance of plant-based foods, responsibly sourced meats, and quality fats. The best part? It's not super restrictive, so you have plenty of nutritious food options. (Start here: How to Adopt a Flexitarian Diet)
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.