Cut out an unhealthy part of your diet today. This may be to remove snacking or to replace it with a healthy snack like dried fruit.
It is of valid belief that our diet can have an affect on our energy levels. Anything that makes your body feel bad is likely to have an affect on our spiritual fitness. I am no expert in this field, all I know is from personal experience. The more I look after my body, the better I feel. Start in small steps to getting your body up to shape.