Great question, and I hope that you are able to modify your lifestyle at this point before things are too late and it becomes difficult to escape from habits and problems that have already developed. I recommend discussing all dietary or exercise changes with your doctor
. In general, green, leafy vegetables are the best things that you can eat. After that, almost all vegetables would be extremely healthy. Next would come fruits, which offer many anti-oxidants and protective benefits, but are also higher in sugar, which can cause problems for some people. Next would come the grains, specifically whole grains that offer many benefits with regards to reducing cholesterol and helping with digestion. The less processed the grain, the greater potential there is for benefit. In the same vein, legumes are also excellent at providing some benefits. Fish and nuts, while containing more calories than other things mentioned above, do have the benefit of including some "healthy" fats and oils that may offer some cardio-protective benefits. In general, less processed products and less red meats are good for all of us, and there are many resources available to help in this transformation. Again, before starting any dietary or exercises changes, please speak with your doctor to make sure it is right for you.