Final answer:
Insulin spikes should be avoided when trying to put on lean muscle because they can lead to increased fat storage and hinder fat burning.
Step-by-step explanation:
When trying to put on lean muscle, it is generally advised to avoid insulin spikes whenever possible, aside from post-workout nutrition. This is because insulin spikes can have several effects on muscle growth. First, insulin promotes the synthesis of protein in muscle, which is essential for muscle growth. However, excessive insulin spikes can also lead to increased fat storage as insulin promotes the storage of glucose as glycogen in the liver and muscle cells. High levels of insulin can also suppress fat burning, which may make it harder to achieve a lean muscle physique.