Try intermittent fasting, for instance:
Brunch2:
2 egg omelette incorporating vegetables (spinach, mushrooms, left over vegetables from last night's dinner, et ), plus a tomato and a few slices of cucumber on the side.
Or a mixed salad with 2 boiled eggs, or a can of tuna or half a breast of chicken.
Or a quick Asian stir-fry with a few prawns or bits of chicken or tofu.
Mid-afternoon snack:
Fruit, or full- fat Greek yoghurt +/- fruit, or a handful of nuts, or a glass of Metamucil (extra fibre!) plus a boiled egg or some fruit/nuts/sunflower seeds,
Dinner:
Lots of vegetables and/or salad, with chicken, fish, prawns, lentils, tofu (or whatever source, of protein you like), plus half a cup of lentils or chickpeas or quinoa.
The important thing is to stay clear of sugar, refined carbs and UPF. They are nutritionally worthless, cause glucose spikes and make you crave more of the same.
Exercise:
Let me count the ways........ there are so many! Do whatever stops you from vegetating on the sofa, even if it's just walking! Lots of online trainers on YouTube - find one you connect with. Lucy Wyndham Read is excellent for beginners and those who are not very fit.
And if all this seems a little overwhelming...... Rome wasn't built in a day but it was built. Personally I found that the benefits manifested themselves very quickly, which in itself was a powerful motivator. Today, at nearly 70, I am fitter than I was in my 40s.
Sorry - I seem to have written half a novel......... but it's all worth it, I promise!!