After a lot of trial and error, I find that is easiest to eat mainly foods that are minimally processed, real foods and to avoid eating many refined carbs. I also rarely eat fast food and limit eating out to 2 or 3 times a week at restaurants where I know I can eat something within the calorie range I want to eat in.
Two more comments:
1. Calories matter a lot. If you eat too much of even very healthy foods then you don't lose.
2. If there are specific foods that you tend to overeat and not be able to it in a limited fashion then don't have those foods around you. For example -- I don't keep cookies in the house because I will eat more of them than would be good for weight loss and health. I occasionally eat one away from home but it isn't good for me to have them at home. On the other hand, I do have a small piece of dark chocolate (60 to 100 Calories) on most days. I can do that without eating the rest of the bar. Other people might be just the opposite.
In general, it is way more easy for me to avoid too many calories by avoiding highly processed foods and being really careful when I eat out. In practice, this usually means I don't eat a lot of refined carbs.
I found the book In Defense of Food by Michael Pollan helpful in talking about eating.
I do eat some of the more indulgent foods occasionally, but generally stick to having them in small portions away from the house.
Tracking food will help with the calories. I track at MyFitnessPal.
When you have been at this a while, you will realize that calories do not matter as much as you think.
To lose, you do need to eat less. But if you eat right, even if you blow the calories you will not gain fat.
But to answer your question: take virtually every reasonable hypothesis from the past fifty years and fold them all into one seemingly reasonable diet that might do us good and probably won't do harm. Thus, the current conception of a healthy diet is one that minimizes salt content and maximizes fiber; has plenty of good fats (monounsaturated and omega 3s) and minimizes bad fats (saturated fats and trans fats); has plenty of olive oil and fish, and little red meat, butter, lard and dairy products. When meat is consumed, it is lean, which keeps saturated fat content down and reduces energy density and thus, supposedly, calories. Dairy is low fat or no fat. The diet has plenty of nuts and legumes and good carbs, which are those with copious vitamins, minerals, antioxidants and fiber (vegetables, fruits and unrefined grains) but few bad carbs (highly refined and sugars which for me is bread, rice, sugar, pasta etc.).
Worked for me. Eat too much of this and you won't gain. Cut the portions and you will lose. I call it the ratchet effect to weightloss.
There's not an easy answer, and there aren't any magic bullet foods. There's a bazillion different ways of eating out there and all of them have worked for various people, but none of us (and I'm guessing not even you, yet) can possibly know which one your body will react best to. That said, the data is pretty clear. If you "do a diet" short-term, you're almost guaranteed to gain the weight back when you go back to your former habits. So focus on creating a way of eating that you can stick with long-term.
For me, that's a weird combination of intuitive eating and a lot of Mediterranean/Middle Eastern foods (because I like them, and they're packed with veggies). For others it's calorie counting (which I can't do, because I get too obsessive and it wrecks havoc on my mental health), for other's it's IF/Paleo/pick your trendy diet of the moment. IMO, the best thing you can possibly do is focus less on which diet to pick and more on learning about nutrition from safe, non-trendy, nothing-for-sale sources. You'll be a lot better informed at that point and be in a solid place to do some trial and erroring. It's taken me about three years to do so, but I can honestly say I eat nothing like I used to, am happy about that, and have lost a good bit of weight to boot. Good luck!
WHAT foods are OK to eat???
