The Real Truth About Belly Fat
By Kathleen M. Zelman, MPH, RD
Who doesn't want a flat belly or chiseled "six-pack abs"? If you are like 60 percent of adults, you are carrying more belly fat than you want. The spare tire is the nemesis of most adults and can be dangerous to your health.
So what is the best strategy for banishing belly fat? Some diet books suggest monounsaturated fats are the answer, while other experts disagree and say weight loss is the real answer.
Losing Weight Trims Belly Fat
Thousands of sit ups won't do you any good unless you lose weight.
There are no magic bullets, special foods or abdominal exercises that specifically target belly fat. The good news – belly fat and the abdominal region are usually the first areas where most people lose weight.
Weight loss is complicated – there are numerous factors that effect weight loss such as exercise, genetics, age, metabolism and where your body prefers to deposit fat.
As you age, your metabolism slows down making it easier to gain weight. You are more likely to pack it on in the belly if you are an adult male, postmenopausal woman (not taking hormones), drink more than 1 to 2 alcoholic drinks daily or smoke cigarettes.
Apples vs. Pears
Whether you are shaped like an apple or a pear, when you lose weight, you will most likely lose more from the central or abdominal region than elsewhere.
"Ninety-nine percent of people who lose weight will lose it in the abdominal region before anywhere else and will lose proportionately more weight from the upper body," explains Michael Jensen, MD, professor of medicine, Mayo Clinic, Rochester. Pear-shaped people exaggerate their pear physique when they lose weight because they become smaller in the midsection, he says.
Penn State University researcher Penny Kris-Etherton, PhD, RD, explains why "visceral fat, the kind tucked deep inside your waistline, is more metabolically active and easier to lose than subcutaneous fat under the skin, especially if you have plenty of it."
"People who are significantly overweight may see quicker results in their belly than someone who has less to lose in that area such as a post-menopausal pouch" says Christine Rosenbloom, PhD, RD., Georgia State University nutrition professor.
Are You at Risk?
Beyond the BMI or body mass index, waist circumference has been touted as a simple and easy test to measure health, weight status and hidden fat, Rosenbloom says.
To assess your risk, use a soft tape measure, lay down and wrap it around your natural waistline (without holding your breath or stomach in) approximately above your hip bone and below your belly button. For men, if your waist size is larger than 40 inches and for women, 35 inches, you may have too much belly fat and may have an increased risk for heart disease and other diseases.
One of the best things you can do for your health is to lose weight to help get your waist circumference to a healthy range, which also may help flatten your belly, Rosenbloom says.
Risks of Excess Belly Fat
Carrying around extra pounds in your mid-section in the form of belly fat, love handles or a pot belly is serious business. Extra weight in this area is more dangerous than fat around your hips and thighs.
Visceral fat is worse than the subcutaneous fat that sits under the skin. Jensen says "extra weight around the midsection is associated with inflammation and a higher risk of health problems such as cardiovascular disease, diabetes, metabolic syndrome and more."
Does Diet Make a Difference?
A study in the American Journal of Clinical Nutrition found that a diet rich in whole grains and controlled in calories trimmed extra fat from the waistline while also lowering blood pressure and the risk of heart disease and other chronic diseases such as diabetes. All of the study participants were obese.
Study participants who ate all whole grains in addition to the daily 5 servings of fruits and vegetables, 3 servings of low-fat dairy and 2 servings of lean meat, fish or poultry, lost more weight from the abdominal area than the other group who ate the same except they ate all refined grains.
Co-author of the study and Penn State professor of nutritional sciences, Penny Kris-Etherton, PhD, RD, explains that "eating a diet rich in whole grains while reducing refined carbohydrates changes the glucose and insulin response and makes it easier to mobilize fat stores. Visceral fat is more metabolically active and easier to lose than subcutaneous fat especially if you have plenty of it and the right conditions are met such as the ones in our study."
When you eat refined foods such as white bread, you trigger a cascade of events starting with an elevated glucose level followed by increased insulin response that cause fat to be deposited more readily.
Enjoying a diet rich in whole grains also tends to be higher in fiber, helping to improve insulin sensitivity which in turn helps the body more efficiently use and lower blood glucose levels and reduce fat deposition.
The 2010 Dietary Guidelines recommends half of your servings come from whole grains. "Eating whole grains exclusively may be difficult and unrealistic for many people – work toward consuming more whole grains as they tend to be high in fiber which satisfies hunger for longer periods and helps you eat less refined grains," Rosenbloom says.
One diet book, Flat Belly Diet, claims belly fat can be lost by consuming a 1600 calorie diet that is rich in monounsaturated fats.
There is little question when it comes to choosing fats, the monounsaturated ones (MUFAs) found in avocados, nuts, seeds, olives, soybeans, chocolate, olive and canola oils are among the best fat choices with proven health benefits such as reducing cardiovascular risk.
But these are not magic foods capable of targeting belly fat. Following a 1600 calorie diet based on the Mediterranean plan, which places emphasis on MUFAs, may likely be the real cause of weight loss, explains co-author of Flat Belly Diet, Cynthia Sass, MPH, RD.
Even though the MUFAs are healthy fats, they are still fats with 9 calories/gram, more than twice the nutrient density of carbohydrates and proteins with 4 calories/gram. "Fats have to be controlled because it is easy to over-eat nuts or guacamole which can undo the health benefits by packing on the pounds," Rosenbloom says.
Role of Exercise
There are no specific exercises that target belly fat. Hundreds of crunches each day won't flatten your belly unless you are also losing weight. Strengthening your abdominal muscles will allow you to hold in your stomach and look thinner, but spot exercises won't banish belly fat, only weight loss can help.
"If you want to lose weight and keep it off, you must eat a healthy, controlled calorie diet and get regular exercise around 60 minutes a day of moderate activity like brisk walking," Rosenbloom says. Jensen suggests people who engage in high-intensity aerobic exercise tend to be leaner around the abdomen.
Real Belly Fat Busters
There is no single, belly busting food. The wealth of scientific evidence suggests a calorie controlled diet rich in fruits, vegetables, whole grains, low-fat dairy, beans, nuts, seeds, lean meat, fish, eggs and poultry is the foundation for a diet that can provide all the nutrients for good health and help whittle your waistline.
Normal weight loss targets belly fat, so, for many people, the best strategy to lose weight is with a calorie-controlled healthy diet and by exercising at least an hour a day.
Sources: Penny Kris-Etherton, PhD,RD, distinguished professor of nutritional sciences, Penn State University; Christine Rosenbloom, PhD, RD, nutrition professor, Georgia State University; Michael Jensen, MD, professor of medicine, Mayo Clinic, Rochester; 2010 Dietary Guidelines for Americans; American Journal Clinical Nutrition, Jan. 2008, pp 79-90; Vaccariello, L and Sass, C. Flat Belly Diet, Rodale, 2008.