Before I go further, let me just say, when I am discussing diet, I do not mean a weight loss plan. I am simply referring to a way of eating. A Vegan diet, a Paleo diet, a Mediterranean diet, a Standard American Diet. You get the point. At its most basic, a diet is simply what you eat. Goals for your diet are a different topic.
When it comes to a way of eating, I am not convinced there is any one particular right or wrong way. Every person is unique. Every person has their own values, health goals, and nutritional needs. Obviously, we all need certain vitamins and minerals. But athletes need a lot more protein than a couch potato. Underweight people need more fat than obese ones. People with food sensitivities need to limit things like gluten or dairy. What is great for one person may be horrible for another. The best thing you can do is figure out what YOUR body needs to be healthy. This is a process of trial and error. Sure, you can spend your hard-earned money on a variety of blood and stool tests to figure this out. Or you can be patient and follow a reliable elimination plan and figure it out for free.
What’s more, even a good diet can be done in a very bad way. You can be a vegetarian and live off of grilled cheese sandwiches and potato chips. You can follow a ketogenic diet and eat only fast food burgers but skip the bread. Done properly, both of these ways of eating can be extremely healthy and beneficial for your health. Done poorly, they can kill you.