I was very underweight most of my life (BMI 15-16) and gained a bit of weight (BMI 18.5 now) during the recent months via training (at home) and eating more. Most of that gained weight is apparently muscle, my body fat is still low and not going up. So, I am not worried about gaining extra fat, and this question is only related to muscle regeneration and growth.

I started going to a gym about a week ago, my primary goal is muscle growth. My trainer told me that eating sugar in the evening is a bad thing because it affects the processes of muscle regeneration and growth. This is how he explained it:

  1. Eating sugar increases insulin
  2. Insulin inhibits somatotropin, the "growth hormone"
  3. Somatotropin is produced mostly during the sleep, thus increasing insulin in the evening, especially before sleeping, will greatly affect muscle regeneration and growth

I am skeptical about two things here:

  1. Q1. Is that insulin spike really that big? I train late in the evenings, and after training, I first eat the dinner and only then eat some cookies or chocolate, 100-200g maximum. (My body mass is 63.5kg at the moment.) I would think that all that sugar is being consumed quickly and there is not that big of a spike of insulin anyway.
  2. Q2. Does insulin production increase during the whole night just because I ate some sugar before going to bed? I would assume that it fades away quickly and then somatotropin has all the time to do its things.

I really like eating sweet food before going to bed, but I don't want to undermine my training.

  • 1
    I would be surprised if there was any sufficient data to support either point and if so it would be marginal. Nutrition is the stepchild of the stepchild of the natural sciences and nutrition related to fitness ... most of this is purely experience based with 100+ years of people working out in the gym. You are a beginner, the experience shows that if you eat enough and eat enough protein, it doesn't matter at all. You have newbie gains. If you have to live a life you don't enjoy, e.g. no sweet food in the evening, it will definitely hurt your training more in the long run.
    – Raditz_35
    Apr 5, 2018 at 7:12
  • (PS) By either point I didn't mean Q1 or Q2 but "this matters" and "this doesn't matter". Please excuse my sloppy English
    – Raditz_35
    Apr 5, 2018 at 7:43

1 Answer 1


At this level I would not be worrying about things like that. The science to support that kind of assertion is woolly at best. If you are new to training there are three things I would be focusing on:

  1. Getting 3+ decent workouts per week. I assume your trainer has this covered.
  2. Get your protein intake up - ideally take a fast-absorbing recovery protein drink just after you train, but in general try to get 0.8-1 gram of protein per pound of bodyweight per day.
  3. Get plenty of rest, a minimum 6 hours sleep per night. Sleep is indeed when your body repairs.

Anything else is just window dressing.

  • 6 hours of sleep is probably the maximum of amount of sleep normal people get in the modern day, Students got school and adults got work...4-5 hours of sleep is normal while 6 hours of sleep means you must have been blessed or something.
    – Ekaen
    Apr 5, 2018 at 11:07

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