How big should my calorie deficit be?

There is no single “ideal” calorie deficit that works for everyone. Maintaining deficits for a long time or maintaining a large deficit can increase the risk of muscle loss, nutrient deficiencies, and symptoms like low energy, irritability, or digestive issues. When the body is in a calorie deficit, it naturally reacts to protect itself and slow down further weight loss. Prolonged or excessive calorie restriction may also lead to rebound overeating or weight cycling. It may also result in alterations of multiple organ systems and physiological functions such as:

• Lower metabolic rate
• Impaired reproductive function
• Effects on bone and muscle health 
• Increased hunger
• Altered appetite-regulating hormones
• Reduced physical activity 

Additionally, calorie deficits are rarely sustainable long-term and only give you a general idea of your calorie needs. It’s often more helpful to focus on overall eating patterns and food quality/choices, such as limiting processed foods and eating adequate protein/fiber, rather than a specific number of calories, in order  to support your long-term health goals.