Why does muscle retain higher lipolytic activity than fat tissue under high insulin levels?

Insulin normally reduces fat breakdown, but our review shows this suppression is stronger in fat tissue than in muscle tissue. In other words, when insulin rises, fat cells slow fat breakdown more than muscle cells do. As a result, muscle keeps breaking down some fat even when insulin is at its highest. This pattern was supported across all 41 assertions we reviewed, with no evidence contradicting it ¹.

We don’t yet know exactly why muscle responds this way — whether it’s due to differences in insulin receptors, enzyme activity, or how signals are processed inside each cell type. But what we’ve seen so far points to muscle being less sensitive to insulin’s fat-storing signal compared to fat tissue itself. This could mean muscle has a built-in ability to keep using fat for energy, even when the body is in a storage mode.

For everyday life, this might help explain why staying active — even during meals or after eating — can support fat use. Moving your muscles may help them keep tapping into fat stores, even when insulin is high.