I am a food major. If you don't really need to lose weight, I suggest eating egg whites and egg yolks.
Egg yolk contains high cholesterol, which will cause various diseases, but it will promote the production of vitamin D and increase the absorption of calcium under ultraviolet irradiation. A small amount of cholesterol is harmless to the body.
And egg yolk contains a lot of minerals, such as phosphorus and iron. The whole egg is very close to the amino acid pattern of the human body, so if eating eggs is not "three highs", it is strongly recommended to eat egg yolk together. It also contains lots of vitamins. I suggest eating an egg every day, the best quality protein, hehe.
Fat gain may be caused by various factors in daily life habits, such as eating snacks, sleeping badly and so on ~