Cholesterol deposition. Food in canada?

My fiance stays in Canada since last one and half years and just returned a month ago to India for 35days before going back to Canada.since last one and half year in Canada he has not been eating regularly and did not filter junk food from his diet.however, when he returned to India for 35 days he had been eating haphazardly as he missed Indian food badly in Canada . as a result he had gained 10kgs in a span of just 35 days . when he was about to return we got his reports done and were shocked to find cholesterol at borderline level .he is too young to get such reports. He also used to get tired very soon when he was here for a month. I am worried for him and want to know is this coolesterol because of this uncontrollable apetite in 35 days or because of irregular and junk food in Canada ? And how to get this into control.? Kindly help