The adrenal gland is affected by high amounts of stress. When the adrenal gland is being pushed too hard by stress reactions, it can cause low blood sugar and weight gain. Stress can lead to a number of health problems if not addressed and it stays at a high level over time. To keep stress under control, you can try meditation, yoga, breathing exercises and exercise. They all have a positive impact on stress. A vacation or hobby can help as well.
Diet can play a major role in the development of inflammation. The diet/inflammation interaction can lead to obesity which in turn fuels the inflammation problem. To see which foods can cause inflammation and which foods can help the problem, read here for diet and inflammation.