Obesity and diabetes mellitus (especially type 2 diabetes) both have their roots in an unhealthy calorie rich diet. Diet planning and a healthy balanced diet thus form an important part of therapy for both these conditions.
An initial dietary strategy in diabetics is to improve food choices to meet the recommendations of the 2010 Dietary Guidelines for Americans and MyPlate the released by the U.S. Department of Agriculture. The basic premise is to reduce fats especially saturated fat and trans fat, cholesterol, as well as sodium in diet. In addition to diet physical activity has to be increased.
The target of mild to moderate weight loss of 5-10% of body weight can improve diabetes control in these patients. Patients with diabetes are thus advised to moderately decrease calorie intake by 250 to 500 kcal/day and increase energy expenditure by regular exercise to improve diabetes.
It is recommended that protein intake accounts for 15 to 20% of total daily calories consumed in all populations. The same recommendations go for patients with diabetes. If the kidney function is normal the usual protein intake should not be modified. However, protein intake above 20% of total daily calories could accelerate the development of kidney disease
Diabetes as well as obesity is associated with heart disease and stroke. Thus reduction of fat in the diet is very important. A person with diabetes needs to choose foods with low saturated fats and take foods containing polyunsaturated fats occasionally and foods high in monounsaturated fats more often.
Saturated fats are found in meats, lard, high-fat dairy products, coconut, palm oil etc. These oils are usually solid at room temperatures and are responsible for high low density lipoprotein (LDL) and cholesterol levels.
Trans fats in addition also lower HDL the good cholesterol. Foods containing trans fats include margarine, peanut butter, shortening, cookies etc.
Polyunsaturated fats are healthy for the heart. They can lower cholesterol levels when eaten in moderation. Polyunsaturated fats are found in vegetable oils such as corn, soybean, safflower oil, and fatty fish such as salmon, mackerel, herring, and trout.
Monounsaturated fats are also good for the heart because they lower LDL cholesterol. These foods include canola oil, walnut oil, olive oil, avocados, olives, nuts, peanut oil etc.
Omega-3 Fatty Acids are one of the best types of polyunsaturated fats with several health benefits. These are found in fish and fish oils and protect the heart as well as decrease insulin resistance in diabetic individuals.
There are three types of omega-3 fatty acids:-
Total fat intake for people with diabetes should be 20 to 35% of total calories. Saturated fat should be limited to less than 7% of total calories, polyunsaturated fat should be limited to less than 10% of total calories, and monounsaturated fat should be limited to less than 20% of total calories. Dietary cholesterol should be less than 200 mg/day.
Fibres are recommended at levels of at least 14 grams for every 1000 calories, or 25 grams for adult women and 38 grams for adult men. Of this 10 to 25 g/day should come from soluble fibre sources. Good sources of soluble fibres include oats, fruits, vegetables, rice bran, cooked beans and psyllium seeds.
Carbohydrates are one of the most important sources of energy. They are found in breads, rice, gains, cereals, fruits and starches. Carbohydrates are broken down to glucose that provides fuel for the body.
Carbohydrates raise blood glucose levels. This means the carbohydrates need to be balanced in diabetic individuals with insulin, medications, and physical activity. While carbohydrates are regulated calories are recommended in moderation. According to Dietary Guidelines for Americans, moderation is the key.
The Food and Drug Administration (FDA) has approved the use of non- nutritive sweeteners like saccharin, aspartame, acesulfame potassium (K), sucralose, and neotame in people with diabetes including pregnant women along with a balanced diet. Saccharin is not suitable for pregnant women because it can cross the placenta.
Glycemic index is a scale (0-100) ranking how quickly a carbohydrate containing food will digest into glucose in the bloodstream. High GI foods break down quickly to glucose while low GI foods break down slowly.
Daily intake should be limited to a moderate amount that is defined as one drink per day or less for women and two drinks per day or less for men. Mixed drinks can raise blood glucose and should be limited.