When I talk about nutrition, I tend to explain it three parts. The What, The Why and The How. All are equally important and play a key role in health and weight. However, if you were to focus on just one of these three with the hopes of positively benefiting the other two, I would tell you to address What you are eating.
I do believe that we are all individual human beings and have different preferences and genetic make up. However, I also think that there can be a clear list of recommendations on what you should eat.
Kinda like 80/20. Eighty out of 100 percent of what I'll recommend will work for you, while the rest (20 percent) will be a bit different based on your preferences and make up.
In general, we should be eating food that is furthest away from man-kind's touch as possible a.k.a "less-processed".
These foods allow the body to operate efficiently without creating any health problems. It is when we put "food like substances" that are not inherently designed for our bodies in our mouths that a host of problems can occur.
These recommendations that I am about to tell you may go against your current beliefs. And that is OK. If what you are doing is working for you then keep on doing it. But if you are not where you want to be with your health/weight then these suggestions are a good place to start.
Grass Fed Beef, Grass Fed Lamb, Bison, Elk, Venison and Pasture Raised Pork.
Chicken and Eggs
Organic Pasture Raised Chicken/Turkey/Duck, Pasture Raised Organic Eggs
Wild Caught, Small Size, Low Mercury Sea Food
Alaskan Salmon, Sardines, Anchovies, Herring and Mackerel.
Kale, Spinach, Brussel Sprouts, Broccoli, Asparagus and Arrugula. (Preferably Organic)
Low Fructose Fruits
Blueberries, Black Raspberries, Blackberries and Cherries.
(Preferably Organic and even frozen works too)
High Quality Fats and Oils
Avocados, Grass Fed Butter, Grass Fed Ghee, Organic Virgin Coconut Oil, Flax See Oil, Organic Extra Virgin Olive Oil.
Black Beans, Garbanzo Beans, Organic Green Beans and Lentils.
Amaranth, Buckwheat, Black/Brown/Red Rice and Quinoa
Nuts and Seeds
Almonds, Walnuts, Pecans, Cashews and Pistachios.
Water, Tea, Kombucha, Coffee and Wine (in moderation) and Coconut Water.
There are many more recommendations per category than the ones listed above. Other things that are important are obviously the quality of the food, how you prepare the food and the source of the food.
As a very quick guideline, you ideally would like to have half of your plate filled with vegetables, a quarter of your plate filled with protein (i.e Salmon, G.F Beef) and the last quarter split between healthy fats (i.e Avocados, Almonds) and fruits or grains. Depending on your goals.
If you starting choosing these types of foods, your body will begin to heal itself and operate at its highest level. Which will in turn allow you to find your ideal weight and health.