Just in case Americans need one more reason to keep weight gain in check and increase their levels of physical activity, there is now more evidence that our lifestyle habits are increasing our risk of experiencing serious illness and premature death. According to a recently published study conducted by the Centers for Disease Control and Prevention, at least 47 million Americans—or about one in five people—have a condition called metabolic syndrome.
Metabolic syndrome is diagnosed when a person has three or more of the following conditions: abdominal obesity, high triglyceride levels, low high-density lipoprotein (HDL) cholesterol levels, high blood pressure, and high fasting glucose levels (see the table below). People who have metabolic syndrome, which is also known as syndrome X or insulin resistance syndrome, are at increased risk for developing type 2 diabetes and cardiovascular disease and are at greater risk of dying from cardiovascular disease and other causes.
Insulin Resistance: The Key Factor to Metabolic Syndrome
Gerald Reaven, M.D., a professor of medicine at Stanford University, was the first scientist to identify that people with high insulin levels have an increased risk of heart disease. In a book that he coauthored, Syndrome X: Overcoming the Silent Killer That Can Give You a Heart Attack (Simon & Shuster, 2000), he estimates that approximately 60 million to 75 million people are insulin resistant. Of these, about 5 to 10 percent will develop type 2 diabetes. The remaining 90 to 95 percent are at risk for developing metabolic syndrome.
Under normal conditions, insulin allows glucose to move into the cells of the body, where glucose is used to produce energy. However, when normal amounts of insulin are not able to transport glucose into the cells, insulin resistance occurs. In other words, the cells resist the action of insulin and the glucose cannot pass through the cell membrane even when normal amounts of insulin are present. When this happens the pancreas must produce more insulin to maintain normal blood glucose levels. People with metabolic syndrome have higher levels of glucose in their blood, although it is still within the normal range, and they are not diabetic.
The cause of insulin resistance in individuals is unknown. It is estimated that about half of the cases of insulin resistance results from genetic variation, which affects insulin’s effectiveness. The ability of insulin to permit glucose utilization may be up to 10 times more efficient in people who are insulin sensitive than in those who are insulin resistant. Insulin resistance is also affected by factors that we can control: body weight (in particular, abdominal fat) and fitness level.
Insulin Resistance and Obesity
Obesity greatly increases the likelihood of insulin resistance; however, it is possible to be insulin resistant without being obese or to be obese without being insulin resistant. Keith Ayoob, a registered dietitian and spokesperson for the American Dietetic Association, explains the role of diet in insulin resistance: “Although diet is one factor in obesity, it is not the ‘cause’ of insulin resistance or diabetes. People tend to become more insulin resistant as they become overweight.”
Treatment and Prevention of Metabolic Syndrome: Tackling Obesity
Dietary approaches to treating and preventing metabolic syndrome vary, but nearly all experts agree that clinical parameters are greatly improved by reducing body weight by as little as 10 percent and increasing one’s level of physical activity.
Ayoob believes that small changes can lead to big improvements: “It’s not about achieving a perfect lifestyle but instead working toward a better one. A 10 percent weight loss can significantly improve health risks.”
To begin to affect weight control, Ayoob suggests that we focus on the successes highlighted by the National Weight Control Registry, which looked at how a variety of people achieved and then maintained a 30-pound weight loss over time. “The National Weight Loss Registry found that people lost weight in different ways: through high-carbohydrate diets, low-carbohydrate diets, fad diets, groups, etc. But to maintain the loss they generally ate diets that were high in fiber, low in fat, and rich in fruits and vegetables. They also made a solid commitment to an active lifestyle (45 to 60 minutes of physical activity each day), and maintained a positive attitude.”
Ayoob points out that obesity stems from excess calories, which can come from a variety of sources. “We eat more food prepared away from home now than ever before. Eating out makes it easier to eat more calories with less portion control. It has also been documented that when we are served more, we tend to eat more. Health professionals need to help people understand moderation and define it for them.”
It takes time to make permanent dietary changes, Ayoob stresses. “You have to gradually balance your diet. It’s not an overnight fix. It has to be a priority to eat fruits, vegetables, and whole grains before eating foods from the top of the Food Guide Pyramid. People are very afraid of giving up all their fun when it comes to food…but people tend to have too many ‘once in a while’ foods. We can’t make every high calorie food just go away: the answer is smaller portions, less often along with more exercise.”
Metabolic Syndrome: The Fitness Connection
Glenn Gaesser, Ph.D., is a professor of kinesiology at the University of Virginia and the author of Big Fat Lies, a book that emphasizes that fitness at any body weight improves health. Gaesser has worked closely with obese clients, encouraging them to change their fitness and eating patterns. According to Gaesser, “Changing either weight or exercise patterns can have profound effects. Exercise is essential because muscle is the biggest tissue in the body—30 to 40 percent of body mass is muscle. It’s the major site of glucose disposal. Inactive muscle is not as sensitive to insulin.”
Many experts recommend that people work toward being moderately physically active for at least 30 minutes per day, most days of the week. Gaesser believes that these recommendations are helpful, but he also encourages people to be more physically active by incorporating short bursts of activity into their routines: “People can ‘work out’ ten minutes at a time by using hand weights while at their desks or while on the phone, or by taking a 2 to 5 minute walk. It may not seem like much but these activities can increase fitness levels.”
Long Term Solutions
Many health professionals believe that society as a whole must undergo a profound change to truly address the problems created by lifestyle factors such as obesity and lack of activity. Ayoob agrees wholeheartedly. “Obesity and metabolic syndrome are not just about food and not about being more active: it’s about a lifestyle. The focus should embody this concept, not just individual foods.”
Ayoob also believes that health professionals must move beyond just telling people what to eat and how to exercise. “We need to readjust our priorities as a society: I believe we can do this, but it will take a concerted effort not just by government, not just by schools, but also by families. Parents need to get on board as role models for how to eat healthfully and be active. When parents don’t model the behaviors, kids are not likely to do them either. When kids see their parents taking care of themselves, they tend to follow along.”
Family meals are crucial to family health because they demonstrate eating habits and build communication. Ayoob explains, “Want to know what your kids are doing?? Schedule dinner…Parents need to get kids in the kitchen to help with family meal preparation. Kids will remember those family meals but not the computer games they played.”
Ayoob isn’t suggesting that families need to cook meals every night. “When you bring in take-out foods, make a salad or steam a vegetable to have along with it. Kids can get involved with that, too. Turn your kids loose in the produce section of the grocery store. Have them pick the vegetables and fruits for the week.”
Like other chronic diseases, metabolic syndrome is a complex, lifestyle-induced illness. Its solutions are not difficult to understand: eat less, exercise more. But as Keith Ayoob suggests, these solutions must become part of everyday life and woven into our societal fabric to be effective. Perhaps we’re ready to listen now.
CLINICAL PARAMETERS OF METABOLIC SYNDROME*
*Note: Metabolic syndrome is defined as having three or more of these risk factors listed in the table.
| Risk Factor |
Defining Level |
| Abdominal obesity |
Waist circumference
Men: > 102cm or 40in
Women: > 88cm or 35in |
| High triglyceride levels |
≥ 150 mg/dl |
| Low high density lipoprotein |
Men: ≤ 40mg/dl
Women: ≤ 50mg/dl
|
| High blood pressure |
≥ 130/≥ 85mmHg
|
| High fasting glucose levels |
≥ 110mg/dl
|
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