Weight-loss programs often accentuate the difference. When sedentary men and women both start exercise programs, men tend to lose body fat, while many women don’t. In one study out of England, men and women were each put on commercial weight-loss programs such as Atkins, Slim-Fast and Weight Watchers. Two months in, the men had lost twice as much weight as the women -- and three times as much body fat. But by six months, the rate of weight loss had evened out between the genders.
The brain’s weight-regulation system considers your set point to be the correct weight for you, whether or not your doctor agrees. If someone starts at 120 pounds and drops to 80, her brain rightfully declares a starvation state of emergency, using every method available to get that weight back up to normal. The same thing happens to someone who starts at 300 pounds and diets down to 200, as the “Biggest Loser” participants discovered.
Your best bet for blasting belly fat is slow, steady weight loss -- not instant one-week results. Steer clear of diets promising double-digit weight loss in just a week or diets that cut out entire food groups or require you to eat just a couple foods. These are typically fad diets that aren't sustainable -- so you're likely to regain any lost weight -- and such diet plans might even interfere with your ability to lose fat in the long run, explains the University of Wisconsin-Madison.
The longest-running study on the link between short sleep and weight gain followed about 68,000 women for 16 years. It found that women who slept 5 hours or less per night gained about 2.5 lbs. (1.1 kg) more, on average, than those who slept at least 7 hours per night, over 16 years. In addition, those who got 5 hours or less were 15 percent more likely to become obese during the study period than those who got at least 7 hours of sleep.
While it is possible to lose 10 pounds in a week, it’s very unlikely—and most nutritionists wouldn’t recommend it. “I generally don't counsel that type of extreme weight loss,” says registered dietitian Maya Feller. “Losing more than a pound a day would be very challenging. Even when I’ve worked with [obese] patients, the most weight I've seen lost in a week in a real world setting—where the person has other obligations and isn’t spending the day in the gym—is 5 pounds.”
Finally, any adult diet that allows fewer than 800 calories per day can be harmful and should only be undertaken under the supervision of a medical professional, according to the 2013 guidelines. People who follow such a diet may experience dehydration, irregular periods (for women), kidney infections and even sudden death, among other health problems, according to the Michigan Department of Health and Human Services. Such diets also increase the risk of developing gallstones.
The main advantage of the low carb diet is that they cause you to want to eat less. Even without counting calories most overweight people eat far fewer calories on low carb. Sugar and starch may increase your hunger, while avoiding them may decrease your appetite to an adequate level. If your body wants to have an appropriate number of calories you don’t need to bother counting them. Thus: Calories count, but you don’t need to count them.