The 40-30-30 diet is not actually a diet as much as a dietary plan. The term "diet" can come with a perception of a temporary change in your eating habits to reach a weight loss goal. The 40-30-30 diet, though it may help you lose weight, is designed more as a way to change your food choices for the long-term to improve your overall health and reduce blood glucose swings.
Carbohydrates
Every gram of carbohydrates you consume contains 4 calories. If you select a food that contains 20 grams of carbohydrates, 80 calories of that food serving are contributed by carbohydrates. Aim for 40 percent of each meal's calories from carbohydrates. Choose complex carbohydrates such as those contributed from fruits, vegetables and whole grains. Limit the high-starch, refined sugar and simple carbohydrates from white potatoes, breads and plain rice.
Protein
Every gram of protein contributes 4 calories to your total consumption. If you choose a food with 5 grams of protein in a serving, that's 20 calories from protein. Select lean proteins like fish, pork and boneless, skinless chicken. If you add protein in the form of nuts, account for the fat content as well. Aim for 30 percent of your day's calories from protein sources of all forms.
Fat
Every gram of fat in a food supplies 9 calories. Select foods that receive less than half of their calories from fat, and choose unsaturated fats. Saturated fat contributes to heart disease and blood pressure concerns that diabetics are already at higher risk for. Limit your consumption of saturated fats. Your overall fat intake should equate to 30 percent of your overall diet. Be sure to account for the fat in all foods. Your carbohydrate and protein selections in each meal will likely contain fat as well.
Application
Determine how many calories you will eat every day. Setting a guideline helps you stay within a target range and reduces the risk of calculation errors. If you choose to consume 2,000 calories per day, a fluctuation of 100 calories either way will have minimal effect on your 40-30-30 ratio. On a 2,000-calorie diet, plan on 800 calories from carbohydrates and 600 calories each from protein and fat. Reduce your daily target by the amount you eat at each meal to help you keep track of what your remaining calories are in each group.
Considerations
The 40-30-30 percentage provides some concerns for diabetics. The carbohydrate guideline is ideal, though some diabetic patients may find that 40 percent of their diet is too much carbohydrates even when the selections are complex, high-quality carbs. Select your fat contributions carefully. Added fat can contribute to high cholesterol and cardiac problems because diabetics are more likely to experience these problems even without 30 percent of your calories from fat. The protein content, if it is more than a few grams of protein per meal, may delay the carbohydrate digestion, which can result in a delayed blood sugar increase. Watch how your body reacts to the protein loads and adapt your meal timing and protein servings accordingly.
