My son is 5yrs 5 months...weighs about 17.2kgs....n needs to potty mostly after lunch....usually thats the only time he pottys....he's fairly a healthy eater n doesn't eat as much junk...his diet contains milk, fruits, veggies, roti, dal, rice....He drinks abt 1 ltr water a day.... he's pretty skinny n has gained only a kg in a year...my husband n i were both skinny kids n i had a super fast metabolism as a child....is any of this linked?? Is my kid ok??? Does he need to gain weight?? can do things to make him gain weight. ...?? Pls help...