By Tracey Greenwood, Ph.D.
No matter the time of year, spring, summer, winter or fall, having a gut is unhealthy, unappealing, limits physical abilities and can even affect sexual performance. Let’s take a deeper look at abdominal fat and a few things you can do to keep that waistline in check.
The Skinny On Abdominal Fat
Excess abdominal fat is not just unattractive; it also increases your risk for many different diseases. Waist circumference is a reliable predictor of visceral fat or abdominal fat. Abdominal obesity is defined as having a waist circumference of >102 cm for men, and this is strongly associated with an increased risk for hypertension, The Metabolic Syndrome, type 2 diabetes, high cholesterol, coronary artery disease, and premature death.
Abdominal obesity also places people at a higher risk for developing a condition called insulin resistance, which increases the risk of type 2 diabetes. Insulin is a hormone that is secreted from the pancreas. Its main role is to regulate glucose levels in the blood by moving glucose into storage sites, such as skeletal muscle and the liver, to be used for energy during physical activity. If people develop insulin resistance, their bodies are unable to store glucose and their blood sugar levels remain high, therefore increasing the risk for type 2 diabetes.
Abdominal obesity is also associated with endothelial dysfunction, which represents the earliest signals of vascular disease. Central adiposity is characterized by the production of adipokines (cytokines which are cell-to-cell signaling proteins) secreted by adipose tissue, and pro-inflammatory cytokines, which induce oxidative stress, leading to reduced nitric oxide availability. Endothelial dysfunction through decreased nitric oxide release inhibits the dilation capability of blood vessels, thereby increasing the resistance of blood flow and causing blood pressure to increase. Weight loss through proper diet and exercise has the greatest potential to improve insulin sensitivity, improve endothelial function, and decrease mortality rates through alteration in adipose tissue function.
In the body, dietary carbohydrates, sugars, and starch are converted to glucose, which indirectly instructs the pancreas to release insulin into the blood. Insulin not only transports glucose into the cells, it stores glucose as glycogen in the liver and muscles. Insulin is the primary fat-building enzyme, converting glucose to fat. When the liver and muscles are filled with glycogen, insulin turns excess glucose into body fat. Insulin also inhibits lipolysis, and decreases the body’s ability to break down stored fat. Diets that are high in carbohydrates are a contributing factor toward weight gain.
When choosing which carbohydrates to include in your diet, you should refer to the glycemic index scale. Carbohydrates are given a measure known as their glycemic index (GI), which rates their effects of blood sugar levels. Carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream have a high GI; carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream have a low GI.
If sticking to eating a low-carbohydrate diet isn’t for you or if you’re looking for a heart-healthy eating plan, then the Mediterranean diet might be more appealing to you. The Mediterranean diet incorporates the basics of healthy eating, which includes olive oil and perhaps a glass of red wine. Research has shown that the traditional Mediterranean diet exerts a cardio-protective effect, reducing the risk of heart disease. Increasing scientific evidence suggests that the Mediterranean diet may not only reduce the risk of cardiovascular disease, but also reduce the risk of cancer, cancer mortality, Parkinson’s and Alzheimer’s diseases, as well as preventing obesity.
The staples of the Mediterranean diet include fresh fruits and vegetables, whole grains, nuts and seeds, legumes, seafood, yogurt, small amounts of wine and olive oil. Olive oil contains oleocanthal, which may reduce inflammation and prevent conditions like heart disease, diabetes, arthritis, Alzheimer’s, and autoimmune diseases, as well as certain cancers. This diet focuses on portion control, emphasizing small portions of high-quality food.
Healthy fats like olive oil and nuts keep you feeling fuller longer than diets that restrict fat or forbid fat altogether. Instead of limiting total fat intake, the Mediterranean diet makes health-wise choices about what kinds of fats you should consume. It focuses on monounsaturated fat found in olive oil, nuts, and avocados; polyunsaturated Omega-3 fatty acids, found in fatty types of fish such as salmon, tuna, sardines, and trout; and fats from plant sources, like flaxseed. This diet also limits your intake of processed and packaged foods, keeping your intake of unhealthy trans-fats extremely low.
Eating more fiber could also have a big impact on decreasing abdominal fat. Fiber helps keep our waistlines slim by producing regular bowel movements and lessening the belly bulge. Fiber also wards off certain diseases. Carcinogens in the intestines bind to it and move through our colons more quickly than they otherwise would, reducing the risk for colon cancer. Fiber’s greatest value, however, is in helping to keep us slim. The recommended daily intake of fiber for adults is 20 to 30 grams per day, with an upper limit of 35 grams. Good sources of fiber include whole grains, vegetables, fruits (preferably with the skin), nuts, seeds and legumes.
Cut Back on Sugar
Most junk foods and processed foods consist of refined carbohydrates and sugars, which when eaten quickly raise blood sugar levels, leading to an increase in appetite and a reduction in the body’s ability to burn fat. Processed foods are highly favored by the food industry and the consumer because they are very inexpensive to produce and are specifically designed to taste good. The enormous abundance and availability of these foods is evidence that they are a staple of the American diet, and this is a major contributor to the prevalence of obesity.
Foods that are high in sugar or refined carbohydrates are digested into large amounts of glucose that quickly enter the bloodstream and cause a rapid rise in blood sugar, resulting in an augmented release of insulin. The additional insulin can impair the body’s ability to maintain consistent blood sugar levels, which can lead to insulin resistance and type 2 diabetes.
Boozing Leads to Belly Fat
Have you seen people who are thin except for their beer bellies sticking out? Well that is the effect of excess alcohol consumption. Alcohol contains “empty” calories, which means it doesn’t contain any nutrients. All of the energy consumed through alcohol will be stored as abdominal fat.
Late Night Eating
To successfully lose weight, the last meal you eat should be at least two hours before you go to bed. The problem with late night snacking is that there isn’t much physical activity done afterward, and this will cause high blood sugar levels and no energy expenditure, causing the excess sugar to quickly be converted to body fat.
Your body begins to shut down a few hours after dinner preparing for sleep, causing your metabolism to become minimized at night. This natural slowing down of your metabolic rate overrides any metabolic or thermogenic boost you would obtain from eating. During sleep, the minimal amount of calories you will burn are those used for cardiovascular and respiratory function and REM sleep. The last meal you eat for the day should consist mainly of lean protein and low glycemic carbohydrates such as fruits and vegetables. You should avoid all starchy carbohydrates like bread, pasta, rice, potatoes, etc.
Sleep and Abdominal Fat
Short sleep duration is associated with obesity, increased abdominal fat, and type 2 diabetes. Sleep patterns consisting of less than 5 hours per night are associated with insulin insensitivity, leading to impaired carbohydrate oxidation and increased risk of type 2 diabetes. The growth hormone (GH) is secreted during the first round of deep sleep. Shorter durations of sleep cause lower GH secretion resulting in the fat-gaining process. Stress imposed on the body due to lack of sleep causes enhanced levels of cortisol in the blood. Cortisol interferes with falling asleep or remaining asleep. The cycle of hormone output, insulin release, and hunger continues. Shift work with its interrupted sleep patterns can be directly linked to belly fat deposit.
Cortisol causes fats and sugars to enter the blood circulation to increase energy for handling stressful situations. Shorter sleep patterns cause an increase in appetite the next day and most often fatty foods are eaten. The blood glucose increases and then decreases, resulting in the repeated presence of cortisol, resulting in a vicious cycle and increased abdominal fat.
Exercise to Reduce Abdominal Fat
Although diet plays the most important role in losing abdominal fat, exercise is a key ingredient in the belly fat-burning process. Weight training is a vital component in decreasing abdominal fat and the key to burning fat at rest. Weight training is an anaerobic activity that will often cause you to burn more calories per minute than aerobic exercise. The calories that you are burning during weight training exercises are mostly calories from carbohydrates (because weight training is usually shorter in duration than endurance exercise), but the calories you burn at rest are mostly calories from fat. The reason you are burning fat at rest is because weight training increases lean muscle mass, which is highly metabolic and therefore increases your basal metabolic rate, which uses your stored fat as energy. To make your body the ultimate fat-burning machine, you should do a combination of aerobic (cardio) and anaerobic (weight training) exercises.
In addition to proper dieting for reducing abdominal fat with aerobic exercise and weight training, you should incorporate abdominal exercises into your exercise routine to strengthen the core. Some of my favorite and most effective abdominal exercises include:
Stability Ball Crunches: Lie on the ball, positioning it under the lower back. Cross your arms over the chest or place them behind your head. Contract your abs to lift your torso off the ball, pulling the bottom of your ribcage down toward your hips. As you curl up, keep the ball stable (i.e., the ball shouldn’t roll). Lower back down, getting a stretch in the abs, and repeat.
Stability Ball Reverse Crunches: Lie on the floor and place hands on the floor or behind the head. Place both of your legs over the stability ball. Bring the knees in toward the chest, rolling the ball up toward your chest until they’re bent to 90 degrees. Contract the abs to curl the hips off the floor, reaching the legs/ball up toward the ceiling.
Captain’s Chair Knee Raises: Using a vertical knee raise chair, start with your legs hanging straight down and slowly lift your knees in toward your chest. The motion should be controlled and deliberate, as you bring your knees up and return them back to the starting position.
Hanging Leg Raises: This exercise is similar to the captain’s chair, except you will hang from a bar or use straps if they are available. You will start with your legs hanging straight down and slowly lift your knees in toward your chest. The motion should be controlled and deliberate as you bring your knees up and return them back to the starting position. Try not to swing as you perform the movement.
Scissor Kicks: Lay flat on your back with your legs straight on the floor. Lift your legs together six inches off the ground. Cross your feet (right foot over left foot); make sure to keep toes pointed up. Return your legs to the original starting position. Cross your feet again, this time left foot over right foot
Seated Knee Raises: Sit in the middle of a bench with your knees and feet together. Grasp the back of the bench and lean backward, making sure your shoulders are pulled back. Lift your knees toward your chest and then extend them back out. Make sure to use your arms to support your body and maintain balance.
30-Second Plank Holds with feet on a Bosu Ball: Lie facedown on mat, resting on the forearms, palms flat on the floor, and place your feet on a bosu ball. Push off the floor, raising up onto toes and resting on the elbows. Keep your back flat, in a straight line from head to heels. Tilt your pelvis and contract your abdominals to prevent your buttocks from sticking up in the air or sagging in the middle.
Depending on your fitness level, I recommend performing 1 to 3 sets of 20-50 reps of each exercise. You should train your abdominals 3 times per week or follow an “every-other-day” schedule. Remember, all of the abdominal crunches and leg raises in the world will not produce a net result of flat, rock-hard abs, without the partnership of diet!
American College of Sports Medicine (2010). Guidelines for Exercise Testing and Prescription, 8th edition. Philadelphia: PA Williams and Wilkins.
Beunza Juan-Jose’, et al. Adherence to the Mediterranean Diet, Long-Term Weight Change, and Incident Overweight or Obesity: the Seguimiento Universidad de Navarra (SUN) Cohort. Am J Clin Nutr, 2010; 92:1484-1493.
Chambliss H.O. Exercise duration and intensity in a weight-loss program. Clin J Sport Med, 2005; 15(2):113-5.
Dorn Joan M., et al. Alcohol Drinking Patterns Differentially Affect Central Adiposity as Measured by Abdominal Height in Women and Men. The Journal of Nutrition, 2003; 133:2655-2662.
Kwon Soyang. Association Between Abdominal Obesity and Cardiovascular Risk Factors in Normal Weight Korean Women. HealthCare for Women International, 2009; 30: 447-452.
Lopez-Garcia E., et al. Sleep Duration, General and Abdominal Obesity, and Weight Change Among the Older Adult Population of Spain. Am J of Clin Nutr, 2008; 87(2): 310-316.
Ludwig David. The Glycemic Index: Physiological Mechanisms Relating to Obesity, Diabetes and Cardiovascular Disease. JAMA, 2002; 287(18): 2414-2423.
Romaguera Dora, et al. Adherence to the Mediterranean Diet is Associated with Lower Abdominal Adiposity in European Men and Women. The Journal of Nutrition, 2009; 139: 1-10.
Samaha F.F., et al. A low-carbohydrate as compared with a low-fat diet in severe obesity. New England Journal of Medicine, 2003; 348:2074-81.
Sanches F.M., et al. Waist Circumference and Visceral Fat in CKD: A Cross-sectional Study. American Journal of Kidney Disease, 2008; 52 (1): 66-73.
Shai Iris et al. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. New England Journal of Medicine, 2008; 359(3): 229-241.
Westphal S.A. Obesity, Abdominal Obesity, and Insulin Resistance. Clinical Cornerstone, 2004; 6(1): 23-31.
Yancy W.S., et al. A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia. Ann Int Med, 2004;140:769-777.