Researchers gave healthy but obese men one of two “high protein” diets. Protein was kept to 30% of total calories in both diets, but the amount of carbohydrate and fat was varied. In the first diet—which they called “low carbohydrate”—the carbohydrate content was kept to a very low 4%, with the rest of the calories coming from fat. In the second diet—which they called “moderate carbohydrate”—the carbohydrate content was kept to 35%, with the rest coming from fat.
If you want to shrink your gut, get enough protein in your diet. In this case, about 25 percent of calories. Why? For starters, protein makes you feel full and helps you build muscle (which increases metabolism, thereby making it easier to lose weight). Just as important, high-protein diets have been shown to be the best way of attacking belly fat. In one study, published in the International Journal of Obesity, Danish researchers put 65 people on either a 12 percent protein diet or a 25 percent protein diet. The low-protein dieters lost an average of 11 pounds, which isn't bad. But the high-protein subjects lost an average of 20 pounds--including twice as much abdominal fat as the low-protein group.
The internal and external obliques, which I like to call "nature's girdle," are located at the sides of the rectus abdominis. They are the muscles you use when you bend sideways at the spine or twist at the waist. They also contract to compress the abdomen, so you should work them just as hard as you work the rectus abdominis. Adding a twist to crunches works, as well as dumbbell side bends, but be careful not to use any jerky motions, especially if you've had back problems.
A 2014 Harvard study found that men who did twenty minutes of daily weight training had less of an increase in age-related abdominal fat compared with men who spent the same amount of time doing aerobic activities, and other studies have shown similar levels of success when guys hit the gym to cut down on fat. The implication: Guys can cut belly fat most efficiently with weight training.
Both moderate and high intensity cardio exercises are beneficial for weight loss. With moderate exercise you are still working hard, but you could carry on a conversation. High intensity exercise you are reaching closer to your max effort, and it is hard to talk in full sentences. High intensity exercises will burn more calories, but moderate exercise will have a higher percentage of fat burn.
Sure, there's your one friend who swears by the Taco Cleanse. And that other friend who ate nothing but broccoli soup for a month and dropped 20 pounds, found the love of her life, and got promoted at work. But before you start blending 80 stalks of broccoli into a cup or crunching your way through a crate of tacos, check out which diets are backed by science. Because don't you want to try one that will do the trick for you?