Lowering the risk of Type 2 diabetes
Source: Nurse Practitioner
Publication date: 2001-09-01

A healthy diet and exercise are the mainstays of controlling one of the most modifiable of all risk factors for diabetes: obesity. Here's what you need to know.

The prevalence of Type 2 diabetes in the United States is alarming. Consider these facts:

* About 2,000 new cases of Type 2 diabetes are diagnosed every day, leading to a threefold increase in the past 40 years.

* One in five people over age 65 has Type 2 diabetes.

* A growing number of children and adolescents are being diagnosed with Type 2 diabetes, which used to be seen only in adults. Obesity may play a role. (Up to 80% of children and adolescents may be overweight when diagnosed.)

Type 2 diabetes is a multisystem disease caused by insulin resistance, the inability of the pancreas to secrete enough insulin, or both. Women with Type 2 diabetes are at increased risk for heart disease, stroke, kidney failure, blindness, neuropathy, amputation, periodontal disease, infections, and possibly dementia. Having poorly controlled blood sugar levels increases the risk for one or more of these health problems. So does the length of time the woman has had Type 2 diabetes; in other words, the more years, the more risk.

Risk--and control

Many personal risk factors make a woman more likely to develop Type 2 diabetes. But experts consider obesity to be the single greatest risk factor. It's also the one risk factor that women are most able to control. Not surprisingly, the number of overweight and obese people in the United States is increasing at the same alarming rate as the incidence of Type 2 diabetes: An estimated 33% of Americans are overweight and 23 % are obese.

What's to blame for the weight crisis? For starters, we need to look at the way we live and eat. Processed and packaged foods loaded with fat and sugar are readily available. We tend to rely on fast foods (also laden with fat and calories) for meals because our lives are too rushed to take time for a meal. And we make little or no time for the physical activities that will help to burn off these calories.

Altering our lifestyle isn't easy. But consider the health consequences of obesity. Besides being at greater risk for diabetes, women who are overweight or obese are more likely to develop cardiovascular problems, cancer, sleep apnea, gallstones, gastroesophageal reflux disease (GERD), osteoarthritis, menstrual problems, and psychological problems (such as eating disorders, social stigmatism, and depression).

Controlling weight

What's particularly frightening is that the risk of developing Type 2 diabetes or cardiovascular problems begins to increase with a body mass index as low as 22 kg/m^sup 2^. For each unit above 22 kg/ m^sup 2^, the risk of developing Type 2 diabetes increases by 25 %.

Weight gain of as little as 11 pounds (5 kg) increases the risk of developing Type 2 diabetes. Abdominal obesity-a waist circumference of greater than 40 inches (100 cm) for men and greater than 35 inches (87.5 cm) for women-seems to carry the greatest risk for Type 2 diabetes.

Losing just 10 pounds (4.5 kg) or 10% of body weight can significantly reduce the risk of Type 2 diabetes, or at least lower blood sugar levels. Diet and exercise are the two most important factors in losing and maintaining weight. They can also improve insulin sensitivity, the major problem in Type 2 diabetes.

Diet is more than what we eat. It's also how much we eat, when we eat, and under what circumstances we eat. Let's take a closer look.

* What we eat. No single diet is the exact diet for women with diabetes or for those trying to prevent diabetes. Instead, the goal should be to make healthy and moderate choices. "Whole," unadulterated foods should be used. Processed, "white" foods should be avoided, or at least severely limited, because they don't contain the same nutrients and fiber as whole foods. Grains, vegetables, and legumes contain fiber, vitamins, minerals, and proteins and should be the mainstay of any diet. Refined and processed foods contain added sugar, fat, and sodium to improve taste and texture. Simple sugars are known to deplete the body of chromium, a mineral that's important in blood sugar control.

* How much we eat. Portion size is important in fighting obesity. For example, a serving of beef should be 2 to 3 ounces, according to the food pyramid. Burgers at a typical fast food restaurant are generally 4 to 8 ounces, and a steak salad at one popular restaurant chain contains 11 ounces of grilled steak. A serving of french fries is calculated at 10 fries; a large serving from a fast food restaurant can be four times that amount. A single meal at a fast food restaurant can average 2,000 calories, the upper limit of total daily required calorie intake for many people. Add two more meals and a fewsnacks throughout the day, coupled with little or no exercise, and you can see why more and more of our waistlines are expanding.

* When and where we eat. Many of us eat on the run, at our desks, or in front of the television or computer. When our minds are on other things as we eat, we may not register the taste or texture of the food. Taste, texture, and the circumstances surrounding when we eat play an important role in reaching satiety and satisfaction. Satiety signals take at least 20 minutes to surface, so shoveling food into our mouths rather than savoring each bite can result in overeating.

A few simple "rules" go a long way toward attaining a healthy diet and preventing obesity:

* Eating should be the only activity you're engaged in (in other words, don't read, watch television, or work on the computer at the same time).

* Don't skip meals; it encourages binge eating.

* Control the portions of the food you eat. Refer to the food pyramid for help.

* Snacks-healthful snacks, that is-are a good thing.

* Chew slowly to aid digestion and to help register satiety and pleasure.

* For optimum digestion, don't eat dinner later than 7 p.m.

Diet for weight loss

A healthy weight-loss program should have a woman eating no less than 1,200 calories a day. If she weighs her ideal body weight of 120 pounds (54.5 kg) at 5 feet 4 inches and exercises moderately, her normal daily caloric need is approximately 1,800 calories.

For weight loss, aim to cut total caloric intake by 300 to 500 calories a day. To calculate how many calories you're currently taking in, multiply your present weight by 14. From this daily caloric intake figure, subtract 300 to 500 calories. This small reduction in daily caloric intake will equate to about a 1 - to 2 -- pound (0.45 to 0.9 kg) weight loss per week.

The food pyramid has a range of servings in each food group. The lower end of the range equates to a 1,600-calorie diet, which is required by most sedentary women and older adults. The high end equals 2,800 calories, required by teenage boys, moderately active men, and very active women. (Highly active men will need more calories.) The middle-of-the-road number of servings will produce a 2,200-calorie diet that meets the requirements of most children, moderately active women, and most sedentary men.

Guidelines for a healthy diet look not only at food groups, but also at percentages of macronutrients ingested. Macronutrients include protein, carbohydrates, and fat. In general, approximately 15% of the total daily caloric consumption should come from proteins, 50% to 60% from carbohydrates, and 25% to 35 % from fats.

Experts also recommend that we consume 20 to 30 grams of fiber daily. Unprocessed, enriched whole grain foods (including cereals, breads, and breakfast bars) may have 5 or more grams of fiber per serving; processed grain foods have as little as I gram of fiber per serving. A 6-year study that followed over 35,000 women found that a high intake of whole grains, cereal fiber, and dietary magnesium played a significant role in preventing diabetes. Another study compared the role of whole grain versus refined grain products and found that the whole grain products may decrease the risk of diabetes in women.

Water-soluble fiber (heicelluloses, mucilages, gums, and pectins, for example) is the most beneficial in lowering blood sugar. It slows the absorption of carbohydrates, causing a slow rise in blood sugar, rather than a rapid rise in blood sugar as is seen with simple carbohydrates such as fruit juices. Water-soluble fiber can be found in legumes, oat bran, nuts, seeds, psyllium, pears, apples, and most vegetables.

Exercise for weight loss

Physical activity has been shown to improve glycemic control and possibly prevent the onset of Type 2 diabetes. Part of the ongoing Nurses' Health Study concluded that physical activity of even moderate intensity and duration substantially reduced the risk of Type 2 diabetes.

The American Diabetes Association recommends 20 to 45 minutes of aerobic exercise, such as walking, at least three times a week. The National Institutes of Health is more stringent in recommending that everyone exercise at least 30 minutes on most days of the week.

This can be spread out over more than one specific exercise session. In fact, the previous Surgeon General recommended walking 10,000 steps a day (approximately 5 miles).

To add up the steps quickly, simply park farther away from the front door at work, the mall, or the grocery store. Walk when you can instead of ride. Take the stairs instead of the elevator or escalator. Take a walk after dinner with family members, or perhaps before dinner, as a wayto wind down and release stress after a busy day. Besides keeping weight down, exercise is great for releasing stress, alleviating and preventing depression, and boosting the immune system.

Also, look at your convenience devices, such as remote controls and riding lawn mowers. Consider abandoning them in place of "manual labor."

Health-promoting lifestyle

A recent study found that helping young adults incorporate health- promoting activities, such as diet and exercise, into their lifestyle may protect against or delay the onset of Type 2 diabetes. This is good advice no matter what age you are.

If we can incorporate good dietary habits, along with exercise and relaxation, into our lifestyle, we'll go a long way toward preventing Type 2 diabetes and its devastating consequences.

Want to learn more? An expanded version of this article, including a list of selected references, will be available soon at our Web site, http://www.springnet.com.