When insulin levels rise, it reduces the breakdown of fat in fat cells by suppressing the enzyme hormone-sensitive lipase.

Insulin helps fat cells store more fat by turning on a special enzyme called lipoprotein lipase that breaks down triglycerides so they can be packed inside the fat cells.

When insulin levels are maximally elevated, fat breakdown is more strongly suppressed in fat tissue than in muscle tissue, meaning muscle continues to break down more fat even under strong insulin signaling.

Elevated insulin levels suppress fat oxidation, thereby inhibiting the fat-burning effects of hydration.

In healthy, lean individuals, insulin reduces the breakdown of fat in both fat tissue and muscle, and muscle tissue requires less insulin to achieve this effect than fat tissue.

When rat fat cells are bathed in a super-sweet, salty solution, insulin doesn’t work as well to stop adrenaline from making the cells release fat — even when insulin is at normal levels.