Does eating too little slow metabolism?

Yes, consistently eating too little can slow down your metabolism. When your body does not receive enough calories to meet its basic energy needs, it adapts by reducing the rate at which it burns energy.

How calorie restriction affects metabolism:
When you significantly reduce your calorie intake, your body enters an energy-conservation mode. It lowers your basal metabolic rate (BMR), meaning you burn fewer calories at rest. This is a protective mechanism designed to preserve energy and maintain vital functions.

Impact on muscle mass:
Low calorie intake, especially with inadequate protein, can lead to muscle loss. Since muscle tissue is metabolically active, losing muscle further decreases your metabolism.

Hormonal changes:
Undereating affects key hormones such as thyroid hormones (which regulate metabolism) and leptin (which controls hunger and energy balance). This can result in reduced energy levels and increased fat storage over time.

Effect on weight loss:
While eating less initially leads to weight loss, prolonged restriction can make fat loss slower and more difficult. The body becomes more efficient at using fewer calories, which can lead to weight loss plateaus.

What to do instead:
Focus on a balanced calorie deficit rather than extreme restriction. Include sufficient protein, engage in strength training to preserve muscle mass, and maintain regular physical activity to support a healthy metabolic rate.