I have done some internet research, but wanted some more advice.
His normal routine is:
Breakfast - glass of whole milk with sugar (will change to semi skim) and a banana
Lunch - salad sandwiches (4 slices of wholegrain bread with olive spread and cucumber/ tomatoes)
Dinner - Vegetarian, lots of wholemeal, veg and lentils
Not sure what else I can change, we dont use alot of fat in our food. Could the banana or olive spread be culprits? He has recently taken up playing badminton as well to incorporate some exercise into his diet.