OP, it is so confusing. Even Mosley's celebrated 800 diet is a total fad to flog bars and powders, just like the 1970s crash diets. Avoid them all.
Focus on two things: eating when you are physically hungry, and when you do, ensure the food is as a PP said unprocessed, mainly plants.
Eg. High protein Skyr or Greek yoghurt with berries for breakfast. Or one slice of wholemeal toast and a boiled egg or half a mashed avocado. Or one tablespoon of no added sugar muesli mixed with grated apple and frozen blueberries to bulk it out with a splash of milk. Or banana milkshake with a drop of vanilla essence, no added sweetener.
Home made veggie soup or crudités and humous or chicken/tuna salad for lunch. If you need more carbs go for no added sugar wholemeal toast with poached egg or sardines in tomato sauce, or a baked potato with home made coleslaw using yoghurt not mayo or cottage cheese with fresh herbs.
For dinner, have about four veg or more with lean protein. Steak with garlic spinach and mushrooms, grilled tomatoes and a few new potatoes or salmon steamed with fennel, ginger and spring onion with pak choi and edamame beans. Or a stir fry of different peppers, carrots, tofu, beansprouts and cashews with brown rice or wholewheat noodles.
Drink water and fruit tea during the day. If you are hungry for a snack have a piece of fruit, or some sliced veg with ham or chicken.
Have cake on your birthday, crisps or ice cream after a ten-mile hike, chocolate at Easter and Christmas. Not as regular snacks.
Don't keep biscuits and other treats in the house. Have several alcohol free days a week and only one glass on other nights unless it's a special occasion.
Move every day 10k steps plus 2 or more full workouts like bootcamp or a gym class.
Find non food items to reward yourself when you need a treat and non food comforts to help you distress.
If you stick to this for a year, you'll be healthy, toned and have lost weight effortlessly. No more yoyoing. If you stick to this for life you will find your natural healthy weight.