What dietary recommendations are suggested for managing type 1 and type 2 diabetes?

Dietary Management for Type 1 and Type 2 Diabetes

For both type 1 and type 2 diabetes, prioritize a diet emphasizing nutrient-dense carbohydrates from vegetables, fruits, legumes, whole grains, and dairy products, with individualized macronutrient distribution, while avoiding sugar-sweetened beverages and minimizing added sugars. 1

Core Dietary Principles (Both Type 1 and Type 2)

Carbohydrate Management

• Choose carbohydrates from vegetables, fruits, legumes, whole grains, and dairy products, emphasizing foods higher in fiber and lower in glycemic load. 1
• The total amount of carbohydrate consumed is more important than the source or type for glycemic control. 1
• Sucrose does not increase glycemia more than isocaloric amounts of starch, so sucrose-containing foods do not need restriction but should be substituted for other carbohydrate sources or covered with insulin. 1
• Eliminate sugar-sweetened beverages entirely to control glycemia, weight, and reduce cardiovascular disease risk. 1

Macronutrient Distribution

• No single ideal distribution exists; macronutrients should be individualized while keeping total calorie and metabolic goals in mind. 1
• A Mediterranean-style diet rich in monounsaturated and polyunsaturated fats may improve glucose metabolism and lower cardiovascular disease risk as an effective alternative to low-fat, high-carbohydrate diets. 1
• Protein intake of 15-20% of total energy is appropriate for most patients. 1

Fat Recommendations

• Limit saturated fatty acids to <10% of energy intake (potentially <7% for elevated LDL cholesterol). 1
• Consume fatty fish rich in EPA and DHA, plus nuts and seeds rich in ALA, to prevent cardiovascular disease. 1
• Omega-3 dietary supplements are not routinely recommended. 1

Micronutrients and Supplements

• Vitamin and mineral supplementation is not recommended for patients without underlying deficiencies. 1
• Exceptions include folate for pregnancy and calcium for bone disease prevention. 1
• Antioxidant supplements (vitamins E, C, carotene) are not advised due to safety concerns with long-term use. 1

Sodium and Alcohol

• Limit sodium intake to <2,300 mg/day. 1
• If consuming alcohol, limit to one drink daily for women and two drinks daily for men, always consumed with food to reduce hypoglycemia risk. 1

Type 1 Diabetes-Specific Strategies

Insulin-Carbohydrate Coordination

• For flexible insulin therapy programs, learn carbohydrate counting to determine mealtime insulin dosing, which improves glycemic control. 1
• The premeal insulin dose should be adjusted based on the total carbohydrate content of the meal. 1
• For fixed daily insulin dosing, maintain consistent carbohydrate intake with respect to time and amount to improve glycemic control and reduce hypoglycemia risk. 1

Hypoglycemia Management

• Treat hypoglycemia with 15-20 g of glucose (preferred) or any carbohydrate containing glucose. 1
• Recheck blood glucose in 10-20 minutes; additional treatment may be necessary at 60 minutes. 1
• Avoid carbohydrate sources high in protein when treating hypoglycemia, as protein increases insulin response without raising plasma glucose. 1

Meal Flexibility

• Multiple insulin dosing regimens allow flexible meal timing and food choices. 1
• Individualized meal plans with intensive insulin regimens accommodate irregular schedules, varying appetite, and activity levels. 1

Type 2 Diabetes-Specific Strategies

Weight Management (Critical Priority)

• Achieve weight loss of ≥5% through reduced calorie intake and lifestyle modification, which improves insulin resistance and glycemia. 1
• Structured programs emphasizing education, reduced fat intake (<30% of daily energy), reduced energy intake, regular physical activity, and regular participant contact produce long-term weight loss of 5-7%. 1
• Standard weight-reduction diets alone are unlikely to produce long-term weight loss; structured, intensive lifestyle programs are necessary. 1

Macronutrient Adjustments for Weight Loss

• Reduce saturated fat to <30% of daily energy intake. 1
• In weight-maintaining diets, replacing carbohydrate with monounsaturated fat reduces postprandial glycemia and triglyceridemia, but increased fat intake in ad libitum diets may promote weight gain. 1

Cardiovascular Risk Reduction

• For elevated LDL cholesterol, limit saturated and trans-saturated fatty acids to <10% (potentially <7%) of energy. 1
• For metabolic syndrome (elevated triglycerides, reduced HDL, small dense LDL), focus on improved glycemic control, modest weight loss, dietary saturated fat restriction, increased physical activity, and incorporation of monounsaturated fats. 1

Common Pitfalls to Avoid

• Do not recommend low-glycemic index diets as a primary strategy, as evidence for long-term benefit is insufficient despite short-term postprandial glucose improvements. 1
• Do not prescribe very high fiber intake (>30 g/day) as the primary intervention, since palatability and gastrointestinal side effects limit adherence. 1
• Do not skip meals when taking insulin or insulin secretagogues, as this increases hypoglycemia risk. 1
• Do not restrict dietary fat excessively in type 2 diabetes without considering that very low-fat, high-carbohydrate diets may worsen triglycerides. 1

Special Populations

Children and Adolescents

• Nutrient requirements are similar to non-diabetic peers. 1
• Individualized meal plans with flexible insulin regimens accommodate irregular schedules and varying appetite. 1

Pregnancy and Lactation

• Nutrition requirements are similar to women without diabetes. 1
• For gestational diabetes, focus on food choices for appropriate weight gain, normoglycemia, and absence of ketones. 1

Older Adults

• Energy requirements are lower than younger adults. 1
• Exercise caution with weight-loss diets, as undernutrition is more likely than overnutrition in the elderly. 1

Nephropathy

• Reduce protein to 0.8-1.0 g/kg body weight daily with microalbuminuria, and to 0.8 g/kg daily with overt nephropathy, to slow progression. 1