Macro partitioning

Dietary carbohydrate intake drives post-prandial increases in adipose tissue lipoprotein lipase (LPL) activity via insulin secretion; high-carbohydrate, fat-free diets significantly increase LPL, whereas fat-containing diets do not.

If you eat a high-carbohydrate, low-fat meal, your body significantly increases the activity of the enzyme (LPL) that stores fat in your fat cells. Eating a fat-containing meal does not trigger this increase to the same degree. This effect is driven by the insulin response to the carbohydrates.