Features June 2012 Issue

Losing Belly Fat Helps Improve Blood Vessel Function

A recent study suggests that the type of diet is less important to heart health than the weight-loss result.

Shedding pounds, especially around your midsection, can help improve your blood vessel function, according to research presented earlier this year at the American Heart Association’s Nutrition, Physical Activity and Metabolism Scientific Sessions.

The six-month weight-loss study found that the more belly fat participants lost, the better their arteries were able to expand as needed to allow blood to flow more freely. Participants were placed on either a low-carb diet or a low-fat diet. And while both diets resulted in improved vascular function, individuals on the low-carb eating plan lost about 10 pounds more, on average, than those following a low-fat diet.

“The take-home message here is: Lose the belly fat regardless if you do it by reducing fat or carbs,” says dietitian Julia Renee Zumpano, RD, LD, who works in Preventive Cardiology & Rehabilitation at Cleveland Clinic. “A low-fat diet may provide a reduction in LDL (“bad”) cholesterol and total blood cholesterol values, for a diet high in saturated fat can lead to a increase in LDL cholesterol. Cutting back on fats can lead to a significant calorie reduction, for fats are the most dense nutrient providing 9 calories/gram, compared to protein and carbs which only provide 4 calories/gram.”

More Than Weight Loss
By reducing belly fat, you’re doing much more for your health than getting your weight down and relieving some of the burden on your heart.

Research indicates that abdominal fat cells produce hormones, specifically leptin, which is released after a meal, and reduces appetite and adiponectin, a protein that affects cells’ responses to insulin, Zumpano explains. “It is still unknown the exact role these hormones play, although greater amounts of abdominal fat disrupts the normal balance of these hormones,” she adds.

It’s also worth understanding the two main types of fat: subcutaneous fat, which resides just under the skin and can be felt; and visceral fat, which exists deep inside around the abdominal organs, and cannot be seen or felt. Visceral fat releases cytokines, which are substances secreted by immune system cells that can promote insulin resistance and inflammation, which in turn increases cardiovascular risk and the development of type 2 diabetes. Visceral fat also is linked to higher LDL and total cholesterol, Zumpano adds.

Dieting Precautions
If you’re motivated to alter your eating style and start a low-fat or low-carb diet, you should be careful not to take either approach too far.

“The risk of a very low-fat diet is the possible lack of essential fatty acids and fat-soluble vitamins,” Zumpano says. “A diet low in fat can tend to be less satisfying therefore may be difficult to follow. A low-carb diet can be more satiating but can lead to elevations in LDL and total cholesterol if high amounts of fatty animal protein is eaten.”

Heart patients should be especially mindful of added sugars and sodium, Zumpano adds. She recommends limiting or avoiding added sugars that do not occur naturally in foods, such as those in sweetened beverages, desserts, sweets, condiments, jellies and syrups, cereals and snacks. You should also limit sodium intake to less than 2,000 mg daily.

“Limit convenience foods, eating out and added salt,” Zumpano explains. “Increase omega-3 fatty acids by eating more fatty fish, such as tuna and salmon, and plant sources, such as flax or chia seeds.”

Don’t Forget to Move
Of course, watching what you eat is only part of the solution to weight loss. Regular exercise that includes a combination of cardiopulmonary activity and resistance training is recommended for most days of the week.

The U.S. Centers for Disease Control recommend that adults get at least 150 minutes of exercise per week. That can be broken into five 30-minute sessions, 10 15-minute sessions or whatever fits your schedule and fitness level.

Stretching and flexibility exercises, as well as balance training, should also be part of your regular routine. If your heart condition or other health concerns limit the types of activities you can engage in, ask your doctor or a cardiac rehab specialist for advice.