Over weight. What should i do?

Hello,    A person who does regular exercise suddenly stops gains weight very rapidly sometimes double. rather than a person who does not exercise at all as there will be a drastic changes in metabolism of their body. They also tend to gain cholesterol also.So donot stop exercise. Walk atleast 5 days in a week. for atleast half an hour per day burning 250-300 kcals / day..Never go for a walk on empty stomach.Have a cup of milk or coffee or tea.or atleast 2 slices of brown bread.Wear a good foot wear. or else you will get heel pain or joint pains. Also eat in time. Avoid junk foods.   Other reasons for weight gain are anaemia,thyroid, other hormonal imbalances..If any of these is positive in investigations see a physician and get them corrected