What is the most effective weight loss diet?

From the Guidelines

The most effective weight loss diet is a sustainable caloric deficit that you can maintain long-term, typically combining reduced calorie intake with increased physical activity, as recommended by the 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults 1.

Key Components of a Weight Loss Diet

• A Mediterranean-style diet is particularly recommended, emphasizing vegetables, fruits, whole grains, lean proteins (especially fish), nuts, seeds, and olive oil while limiting processed foods, added sugars, and refined carbohydrates.
• Aim for a moderate caloric deficit of 500-750 calories per day, which should yield a healthy weight loss of 1-2 pounds weekly.
• Portion control is essential, as is regular physical activity (150+ minutes of moderate exercise weekly).

Implementation

• Start by tracking your current food intake for a week, then gradually reduce portions and substitute healthier alternatives.
• Drink plenty of water, plan meals ahead, and include protein with each meal to increase satiety.
• This approach works because it creates a negative energy balance while providing essential nutrients, reducing inflammation, and supporting metabolic health.

Supporting Evidence

• The Mediterranean pattern specifically has been shown to improve cardiovascular health markers while being sustainable long-term, which is crucial since temporary diets typically lead to weight regain once normal eating patterns resume 1.
• A variety of dietary approaches can produce weight loss in overweight and obese adults, including low-calorie diets, low-fat diets, and Mediterranean-style diets 1.
• The American Diabetes Association recommends a dietary approach that emphasizes whole grains, fruits, vegetables, and lean proteins, and limits added sugars, saturated fats, and refined carbohydrates 1.

From the FDA Drug Label

Use for weight loss in overweight adults, 18 years and older, when used along with a reduced-calorie and low-fat diet Directions read the enclosed brochure for other important information diet and exercise are the starting points for any weight loss program. use with a reduced-calorie, low-fat diet and exercise program until you reach your weight loss goal

The most effective weight loss diet is a reduced-calorie and low-fat diet combined with an exercise program 2 2.

• Key elements of the diet include:
  • Reduced-calorie
  • Low-fat
• It is essential to combine the diet with an exercise program to achieve effective weight loss.
• Most weight loss occurs in the first 6 months of the program.

From the Research

Effective Weight Loss Diets

There are various diets that can be effective for weight loss, including:

• High-protein, low-carbohydrate diets, which may promote greater weight loss in the short term 3
• Intermittent fasting, which can also lead to greater weight loss in the short term, but may have adverse effects 3
• Low-fat diets, low-carbohydrate diets, high-protein diets, very low-calorie diets with meal replacements, Mediterranean diet, and diets with intermittent energy restriction, which have been shown to be effective for weight loss in various studies 4
• Diets that focus on good food quality and create a negative energy balance, which are fundamental for promoting health and weight loss 3

Key Principles for Weight Loss

The following principles are key for effective weight loss:

• Setting realistic goals for weight loss 4
• Pursuing a balanced dietary plan tailored to individual needs, preferences, and medical conditions 4
• Achieving a stable Healthy Eating Food Diversity Index, eating more protein, eating more fiber, engaging in more physical activity, sleeping better, and eating less ultra-processed foods 5
• Individualizing strategies for weight loss and maintenance, and choosing the best strategy based on patient preferences 6

Comparison of Different Diets

Studies have compared the effectiveness of different diets for weight loss, including:

• The POUNDS Lost study, which found that low-fat and lower carbohydrate diets resulted in modest weight loss, with no significant dietary difference 5
• A review of evidence-based dietary strategies for weight management, which found that there is no single best strategy for weight management, and that strategies should be individualized 6
• A study comparing the effectiveness of orlistat and liraglutide for weight loss, which found that liraglutide was more effective and sustained, especially when combined with physical activity 7