I've never been on a diet in my life - but the Misses tried the keto diet recently and I joined her for 6 months - we cut out ALL carbs - no bread, no sugar no pasta etc and removed all processed food from my diet and particularly corn / vegetable oils.
We just ate food high in good fats - animal fats and protein, cooked in lard, ate real butter, lots of meat - eating all the fat on the meat too, loads of cheese, eggs, avocado, full fat double cream in coffee instead of milk and non tuber vegetables.
The lbs fell off me, I wasn't particularly overweight to start with, but I now have a slimmer more toned shape in my fifties than I ever have had - and I went to the gym religiously from the age of 20 - 40.
We ate fat and got thin!
Basically we have been lied to:
Margarine is very bad for you - butter is good for you!
Vegetable oil is the devils spawn - olive oil and lard is the healthy option.
Now they want to remove real meat from your diet and feed you synthetic lab grown meat or insects lol
The answer to a healthy lifestyle do not lie with big pharma and their drugs (or injections) - they make vast sums from pushing these drugs on you - and they certainly don't want you to get better and stop using them!
Don't eat anything that comes out of a factory, don't eat anything processed, don't eat anything with listings in the ingredients that you don't understand and are not familiar with.