As Americans' waistlines continue to expand, contributing to a burgeoning epidemic of type 2 diabetes, the scientific jury is in and the verdict is clear: weight loss and increased physical activity is directly related to improved diabetes control.
To help Americans fight the dramatic increase in type 2 diabetes, Joslin Diabetes Center has crafted new nutrition and physical activity guidelines for overweight and obese individuals with type 2 diabetes and those at risk for developing diabetes (pre-diabetes).
"Since obesity doesn't seem to be slowing down and the complications of diabetes are so serious, we were especially alarmed about the health of the American public. We felt the best way to impact the largest number of people was to strengthen our nutrition guidelines," says James L. Rosenzweig, MD, head of Joslin's clinical guidelines committee.
The team of physicians, dietitians, exercise physiologists and educators spent months reviewing the scientific literature to draw up new guidelines. "The search was on for guidelines that would improve insulin sensitivity, cardiovascular health and reduce body fat. And most importantly, we wanted to deliver a plan that makes clear what people need to do to achieve their goals," says Dr Rosenzweig, who also is director of Joslin's Disease Management Program and Assistant Professor of Medicine at Harvard Medical School.
The new guidelines recommend approximately 40 percent of a person's daily calories come from carbohydrates; 20 to 30 percent from protein (unless the person has kidney disease); 30-35 percent come from fat, (mostly mono- and polyunsaturated fats); and at least 20-35 grams of fiber. To initiate and continue weight reduction, a modest goal of one pound every one to two weeks is advised by reducing daily caloric intake by 250 to 500 calories. Total daily calories should not be less than 1,000 to 1,200 for women and 1,200 to 1,600 for men. A target of 60 to 90 minutes of modest intensity physical activity most days of the week with a minimum of 150-175 minutes/week is encouraged and should include cardiovascular, stretching and resistance activities to maintain or increase lean body mass.
Two out of three people in the US are overweight or obese, resulting in a skyrocketing rate of type 2 diabetes that now affects at least 18.2 million Americans, including an increasing number of young people. An estimated 41 million Americans have pre-diabetes and are at risk of developing full-blown type 2 diabetes unless they lose weight and increase physical activity. Diabetes is a leading cause of heart disease, stroke, blindness, kidney disease, amputations and other complications.
"Setting the standards for diabetes treatment for more than 100 years, Joslin Diabetes Center's approach to diabetes management has always been to focus on the individual and not dictate a 'one size fits all' strategy. While these guidelines are very straightforward, Americans should meet with their healthcare team so they can adapt the guidelines to meet their personal needs," says Osama Hamdy, MD, PhD, clinical director of Joslin's Obesity Program and an obesity researcher, who co-chaired the committee that developed the new guidelines.
"Eating smaller portions, modest carbohydrates and slightly more protein with careful selection of fat, protein and carbohydrate sources is the way to go if you are overweight or obese and have diabetes or pre-diabetes and normal kidney function. These recommendations can help people lose weight, have better diabetes control and prevent serious cardiovascular complications," Dr Hamdy adds.
Catherine Carver, MS, ANP, CDE, director, Educational Services and New Clinic Program Development, also co-chaired the workgroup that wrote the guidelines. Amy P. Campbell, MS, RD, CDE, Education Program Manager of Joslin's Affiliates Programs/Disease Management Program, also was integral to developing the guidelines.
Among the highlights of the new Joslin guidelines are the following recommendations:
Carbohydrate: Approximately 40 percent of a person's daily calories should come from carbohydrate; the total should not be less than 130 grams daily. This is a significant change from Joslin's previous recommendations that promoted a higher carbohydrate intake. Scientific data show that reducing one's carbohydrate intake while simultaneously increasing healthier protein and fat choices may be a better approach to weight control. It may also help decrease cardiovascular disease in overweight people with type 2 diabetes. The best sources are fresh vegetables, fruits and beans. Whole grain foods are preferable to eating pasta, white bread, white potatoes and low fiber cereal. Fiber intake should be approximately 50 grams daily if that amount can be tolerated; a minimum of 20-35 grams per day is recommended and an external supplement may be needed. High-fiber foods include fruits, vegetables, whole grain cereals, breads, nuts and seeds.
Fat: Approximately 30 to 35 percent of a person's daily calories should come from fat. Most should come from mono- and polyunsaturated fats, such as olive oil, canola oil, nuts, seeds and fish (especially those high in omega-3 fatty acids, such as salmon, mackerel, lake trout, herring and sardines). Foods that are high in saturated fat, such as beef, pork, lamb and high-fat dairy products (cream cheese, whole milk) should be eaten in small amounts. Foods that are high in trans fats such as fast foods, commercially baked goods, crackers, cookies and some margarines should be avoided. Cholesterol intake should be less than 300 mg daily; or less than 200 mg in people with an LDL ("bad") cholesterol that is more than 100 mg/dL.
Protein: While anyone with signs of kidney disease should consult their provider before increasing the daily amount of protein, approximately 20 to 30 percent of a person's total calories should come from protein. This is a higher percentage than Joslin recommended in the past. Scientific data reveal that eating more protein helps people feel "full" and thus causes people to eat less calories overall. Protein also helps to maintain lean body mass during weight loss. Examples of protein include fish, skinless chicken or turkey, nonfat or lowfat dairy products and legumes such as kidney beans, black beans, chick peas and lentils.
Weight Loss Guidelines: A modest weight loss of one pound every one to two weeks is advised. Reducing daily calories should be by 250 to 500 calories; total daily calories should not be less than 1,000 to 1,200 for women and 1,200 to 1,600 for men. Weight loss is different for each person and should be continued until a person reaches a target body mass index, or BMI (ask your provider about how to obtain this measurement.) Meal replacements, such as shakes, bars and ready-to-mix powders that match these guidelines can be helpful for some people. Blood glucose patterns often change with these types of replacements and thus people should monitor their blood glucose.
Physical Activity Guidelines: Physical activity is extremely important to a weight loss plan. A minimum of 150 to 175 minutes of moderate intensity physical activity is recommended. Examples of this include walking, biking, swimming and dancing. A target of 60 to 90 minutes most days of the week is encouraged. Physical activity should be a mix of cardiovascular, stretching and resistance activities to maintain or increase lean body mass.