Because many individuals with T2DM are insulin resistant and overweight or obese, nutrition therapy often begins with strategies that reduce energy intake and increase energy expenditure through physical activity. The optimal macronutrient distribution of weight loss diets has not been established. Studies designed to reduce excess body weight have used a variety of energy-restricted eating patterns with various macronutrient intake, and some included physical activity and ongoing follow-up support. Clinicians should collaborate with overweight or obese individuals with diabetes to develop healthful eating plans that reduce energy to promote weight loss. An eating plan should include appropriate food choices, and portion size needs to reflect energy requirements to ensure appropriate energy balance (Evert, 2014).
Maintenance of weight loss requires an intensive program with long-term support (Evert, 2014). One study concluded the failure of initial weight loss of 6% after 12 weeks of intensive weekly contact with improvement in glycemic control to be sustained at an 18-month follow-up was likely due to a lack of continued contact with a health professional (Ash, 2003). A study comparing a high-monounsaturated fat diet to a high-carbohydrate diet concluded only the high-monounsaturated fat diet group was able to maintain weight loss at 18 months compared to the high-carbohydrate diet group (60% carbohydrate). The authors note the intense, year long behavioral intervention delivered by registered dietitians influenced the dietary compliance and positive outcomes achieved in the study (Diabetes Prevention Program Research Group, 2009).
See the ICSI Prevention and Management of Obesity for Adults guideline for recommended lifestyle strategies.