HIIT was originally developed by track coaches to train runners, but it has crossed over to the fitness industry due to its fat-burning benefits confirmed many times over in scientific studies (see "HIIT Findings"). A lot of these studies found that subjects performing HIIT burned significantly more body fat—and in less time—than those who did steady-state cardio programs.
SOURCES: WebMD Feature: "With Fruits and Veggies, More Matters." 2005 U.S. Dietary Guidelines. Elizabeth Ward, MS, RD, author, The Pocket Idiot's Guide to the New Food Pyramids. Elaine Magee, MPH, RD,author, Comfort Food Makeovers. Brian Wansink, PhD, professor and director, Cornell Food and Brand Lab, Ithaca, N.Y.; author, Mindless Eating. Barbara Rolls, PhD, professor of nutritional sciences; and director, laboratory for the study of human ingestive behaviors, Penn State University; and author, The Volumetrics Eating Plan.
A diet that’s low in fat and carbohydrates can improve artery function, according to a 2012 study by Johns Hopkins researchers. After six months, those on the low-carb diet had lost more weight, and at a faster pace. But in both groups, when weight was lost—and especially when belly fat shrank—the arteries were able to expand better, allowing blood to travel more freely. The study shows that you don’t have to cut out all dietary fat to shrink belly fat. For heart health, simply losing weight and exercising seems to be key.
Research has shown that with intermittent fasting, blood pressure is reduced, levels of sugars and fats in circulation are improved, and inflammation, an indicator of heart disease risk, can be limited. Every week there is a day when you are eating a reduced amount of calories compared to the other days, to achieve this. He has dieters follow a specific four-week eating plan, including some days where the calorie count is about 1,600, and other days where it is 900. (The average caloric intake for women is about 1,800 a day; for men, 2,500, according to government statistics).
In a way, moderate-intensity physical activity is that "magic pill" a lot of people are looking for, because the health benefits go beyond keeping your waistline trim: Not only can it reduce your risk of cancer, stroke, diabetes and heart attacks, but studies have shown that physical activity can significantly improve the moods of patients with major depressive disorders.