I looked into this about a year ago when I wanted to lose about a stone. I bought a book called The Full Diet, which was written by a British NHS doctor and nutritionalist. It was a revelation.
Essentially, assuming you have no other medical conditions which are affecting your metabolism, the secret to losing excess weight and maintaining a healthy and stable weight indefinitely is to control your blood sugar, not count calories or consciously restrict your intake. If your metabolism is healthy your body will do this for your. If your blood is surging with sugar, your gut bacteria is destroyed by artificial chemicals and there is a disconnect in the messaging between your gut and your brain, it can't.
High blood sugar is extremely bad for you, especially for your brain, so your body produces insulin to get rid of it. The insulin can't force it to be excreted or burned up, so it converts the blood sugar into fat cells. These are then deposited around the body as your blood circulates. It dumps it in the easiest places first, which is your liver, then around your vital organs (visceral fat) and lastly around the muscles and under the skin, which is the fat you can see and makes your clothes tight.
If you eat foods which reduce and stabilise your blood sugar your body goes into fat burning mode and you will lose weight rapidly and it will stay off. And you won't feel hungry or have food cravings.
If you merely count calories and those calories come in the form of foods which raise blood sugar, you will continue to gain weight regardless of exercise. And you'll lack energy and constantly feel hungry and miserable.
Basically, cut out all simple (refined) carbohydrates, all refined sugars and all processed food. That means no flour-based foods, so no bread, pasta or any bakery products. And no high-sugar/high starch vegetables like potatoes, parsnips, sweet potatoes, and no refined sugar or high sugar fruits like bananas, pineapples grapes, mangoes or fruit juice (eat moderate-sugar whole fruits, not the processed juice).
And cut out all ultra-process food. So no e-numbers or chemicals. If it didn't walk, swim, fly or grow out of the ground, it isn't real food and you shouldn't eat it. And only natural unprocessed oils and cooking fats, so olive oil, butter, lard, and pure rapeseed oil. Never hydrogenated stuff. And cut out or greatly reduce alcohol consumption, and never drink every day.
I've been eating like this for a year now and the results have been dramatic. I lost the desired stone, I eat at regular times, I never snack and I can tolerate the normal feelings of hunger which tell me when it's time to eat without experiencing food cravings. I never over-eat anymore and I don't have to think about it.
I also follow a regime of only eating between the hours of 10 am and 6 pm. Between those times I eat healthy food in normal quantities and I don't count calories or exclude fat. That means the full range of fruit and vegetables (excluding those mentioned above), all kinds of fresh meat and fish, all whole diary products (never "low-fat" or processed), eggs, all herbs, spices, nuts, pulses and low carb grains like bulgur wheat. Everything freshly prepared.
I never eat anything from a can or packet unless it is made from unprocessed natural products that I could buy from a butcher of a greengrocer. Everything is fresh.
I've found eating fresh is a lot cheaper than processed and doesn't actually take any longer to prepare.
I am lucky though, in that I live alone, so I do the shopping and I control what goes into my fridge and cupboards, and I am the one cooking my food. The difficulty comes when you live with other people or in a family. If you've got teenage kids, good luck keeping processed food out of the house.
But trust me, if you can do it, eat only natural, low carb and sugar foods and only eat within one eight hour window in every 24 and the weight will fall off you.
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