The least likely explanation for this would be that they're training at different intervals, or one is training harder than the other.
The most likely reason is that the way the other person's genetics are most people cant gain muscle as well as others because of disease or their body structure.
Hope this helped!
Answer:Severe.
Explanation:It would be moderate if you choose not to, or if you parents or care- takers could not be their in time to fix the food. Not to mention if you were an adult, it could be a different way such as, you forgot food or you can't go get it or eat because you are on your shift.