Real talk: It could take weeks or months to see the metabolic effects of exercise on the scale, and even then, building muscle, which is denser than body fat, could lead to weight gain. "Do what you like because it’s good for you," Dr. Seltzer says, noting the way exercise is awesome for your heart, mental health, and more—and that not all measure of progress can be seen on the scale.
A 2012 study also showed that people on a low-carb diet burned 300 more calories a day – while resting! According to one of the Harvard professors behind the study this advantage “would equal the number of calories typically burned in an hour of moderate-intensity physical activity”. Imagine that: an entire bonus hour of exercise every day, without actually exercising. A later, even larger and more carefully conducted study confirmed the effect, with different groups of people on low-carb diets burning an average of between 200 and almost 500 extra calories per day.
Little treats keep you from feeling deprived, so every day, allow yourself a bit of something you love (aim for 150 calories each). This kind of moderation is the difference between a "diet" and a lifestyle you can stick with forever. For salon owner Caitlin Gallagher, who lost 125 pounds, that meant replacing her nightly bowl of ice cream with a square of chocolate; social worker Brittany Hicks, who lost 100 pounds, started baking mini versions of her favorite pies.
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)

Sure, you can lose weight quickly. There are plenty of fad diets that work to shed pounds rapidly -- while leaving you feeling hungry and deprived. But what good is losing weight only to regain it? To keep pounds off permanently, it's best to lose weight slowly. And many experts say you can do that without going on a "diet." Instead, the key is making simple tweaks to your lifestyle.