I'm on the Keto Diet. Low carb, high fat. - With lots of Protein for gainz.
I hate cooking, so keep it simple and quick. Couple cups of Beans and Peas. Couple snags.
Basically eliminates all fast food.
Don't eat Breakfast or Lunch, no snacks, will have a low-carb shake at lunch time if I am exerting myself.
I do Fire fighting training on Monday nights, Emergency Service training on Wednesday nights, so I skip those days as they are physically intensive.
I have a 10+ hour training session for fire fighting or emergency services on a Sunday a couple times a month.
So usually I go to the Gym on Saturday, Tuesday, Thursday, Friday for a good hour-hour and a half... And I will do a 15-20km (9-12 miles) walk 1-2 times per week with short 5km (3.1 mile) walks whenever I can fit them in.
Being fit and eating healthy is important, it's great when you have a routine set in.
If you can't manage a routine... Then start by having motivation from friends and family, get them to join in and push you along.