How should i go about loosing weight with stomach problems like diverticulitous gastritious might have hernia too ?

Same way: as others eat less reg exercises

Eat less/move more: The key to weight loss is always eating less calories and moving more. I suggest that you exercise for 30 minutes daily, walking is fine. Also make sure that the food you eat is nutritious, no junk food or empty clories like sodas or sweet snacks. Eat lots of fresh fruits and vegetables as tolerated. Take a probiotic daily on an empty stomach.

Calories in n out: See the excellent answers on "weight loss". You basically need to burn more calories than you take in. Increase your exercise, choose healthier, less-caloric foods and drinks. The nice thing is that if u build more muscle you will even burn more calories while you sleep! and don't focus too much on weight. Focus more on pants-size, etc. Muscle weighs more than fat but that's ok--its good wt.

Life style change: Start an active life style Eat less at a time don't skip meals eat healthy breakfast use salads avoid soda avoid sweets avoid carbs drink plenty of water exercise daily