From the Guidelines
A calorie deficit is recommended for overweight or obese individuals as a means of improving nutrition, longevity, and health, but it should be implemented in a way that prioritizes nutrient-dense whole foods and sustainable lifestyle changes. The most recent and highest quality study, published in 2024 1, recommends a calorie deficit of 500-750 kcal/day for weight loss in individuals with type 2 diabetes and overweight or obesity. This can be achieved through a variety of dietary approaches, including high-frequency counseling and behavioral therapy, as well as individualized nutrition plans that create an energy deficit regardless of macronutrient composition.
Key Recommendations
- A modest calorie deficit of 300-500 calories per day is typically recommended for weight loss, combined with regular physical activity and adequate protein intake (about 0.8-1g per pound of body weight) to preserve muscle mass 1.
- Nutrition recommendations should be individualized to the person’s preferences and nutritional needs, and should prioritize whole, nutrient-dense foods over ultra-processed foods 1.
- Intensive behavioral lifestyle interventions, including high-frequency counseling and behavioral therapy, can be beneficial for weight loss and should be considered when available 1.
- Long-term weight maintenance programs, including monthly contact and support, ongoing monitoring of body weight, and regular physical activity, are recommended for individuals who achieve weight loss goals 1.
Rationale
The recommendation for a calorie deficit is based on the evidence that weight loss can improve health outcomes, including reducing the risk of chronic diseases such as type 2 diabetes and cardiovascular disease 1. However, it is also important to prioritize nutrient-dense whole foods and sustainable lifestyle changes to minimize the risk of nutrient deficiencies, muscle loss, and other potential negative effects of calorie restriction 1. By focusing on whole foods and sustainable lifestyle changes, individuals can achieve a healthy weight and improve their overall health and well-being.
From the Research
Calorie Deficit and Nutrition
- A calorie deficit is recommended as a means of improving nutrition, as it can help reduce the risk of cardiometabolic diseases and improve overall health span and quality of life 2, 3.
- Calorie restriction (CR) with adequate nutrition is the only non-genetic, non-pharmacological intervention that extends lifespan in model organisms and protects against the deterioration of biological functions, delaying or reducing the risk of many age-related diseases 4.
Calorie Deficit and Longevity
- Evidence from observational, preclinical, and clinical trials suggests that calorie restriction can increase life span by 1-5 years with an improvement in health span and quality of life 2.
- Moderate and prolonged calorie restriction in healthy adults without obesity can have beneficial effects on health outcomes, including changes to anthropometrics, energy metabolism, cardiometabolic health, inflammation, and immune function 3.
Calorie Deficit and Health
- Calorie restriction presents a novel and effective therapeutic approach for improving healthspan and biomarkers of lifespan, with continued CR under medical supervision accompanied by persistent and beneficial effects on health outcomes independent of weight loss 3.
- A low-calorie diet with a low fat or carbohydrate content has been recommended for weight loss, and some macronutrient composition-based diets, such as the ketogenic diet or high-protein diet, could be considered in some cases 5.
- Nutrition, including calorie intake, affects the time span in which health and functional capacity are maintained, and feasible nutritional strategies can delay aging and/or prevent diseases 6.