HMMMM a good decision at d point to think abt ways to loose weight
u need to do some lifestyle modifications
changes in eating habits: more of fibre, less of fried stuff, drink more fluids - must consume atleast 3-3.5 lts of water
regarding asthma try to b away from allergens,dust and pollen.
as u thought abt loosing weight will help u in preventing sleep apnoea syndrome.