By all that is holy can someone suggest a diet plan for someone with no consistent schedule and little prep time? I have got to shed some lard but everything I've looked at seems to assume you're a full time stay at home cook.
When I was single I hated to cook, and needed to drop about 65 pounds so I could join the Navy. I bought canned tuna for my protein. I would cook/grill hamburger, too, and occasionally chicken, but I ate a metric crap-ton of canned tuna.
Proteins: canned tuna, deli meats, cheese, hummus.
Carbs: frozen and canned veggies, beans/legumes, oats (steel cut or long-cook oats, not instant oatmeal).
Fruit: whatever I wanted.
No-no's: breads, pastas, candy, ice cream, cereal. Beer/booze is also 'bad' (beer has carbs, booze has sugars), but I had them anyway.
Drink water. No sports drinks, no electrolytes, nothing but water (or black coffee).
You need to read labels enough to restrict your calories. I ate about 1,200-1,500/day, and exercised 30 min-1 hour a day.
Edited to add, if you want to lose weight fast(er), go on a high protein/low or no carb diet. There are plenty of online resources on how to do that. The more complicated your diet, the harder it is to plan for and stay on. My plan above is what worked for me, and is the 'common sense' approach of limiting bad calories/bad carbs, upping protein, and exercising to ensure a calorie deficit. I lost 65 pounds or so in about 8 months.