[matthiasak]

Just to add a little more detail, insulin spikes themselves (hormonal response to food, etc) cause other hormonal responses that trigger everything from weight gain, to oil production, to lack of sleep and stress response. One particular thing to note is how much the strong and hard insulin spikes raise cortisol levels. Cortisol production can highly affect the level of oil and stress you are under, further throwing your body into a loop. If you are causing yourself to create and release a high excess of cortisol, then you will find that the rest of your body's systems (skin, hair, cardiovascular, etc) will have profound and often adverse affects.