Does Keto and Carnivore Lower Your BMR

On ketogenic and carnivore diets, the body adapts to use stored body fat as fuel, so BMR does not significantly decrease when eating nutrient-dense animal protein at 1,000 calories. However, if intake remains very low for extended periods (weeks to months), the body may perceive this as famine and begin reducing BMR, causing symptoms like feeling cold, hair loss, and stalled weight loss. To prevent this, individuals should ensure adequate protein intake and intentionally consume more fat (like butter, tallow, or bacon grease) to signal to the body that energy needs are being met.