Avoid processed foods
Skip the fad diets, and simply start avoiding processed foods. Anything processed, like bags of chips, salty frozen meals, fast food, etc., is going to be loaded with salt, calories, and probably a dose of chemicals as well.
You’re better off eating whole foods, like fruits, veggies, whole grains, and healthy fats. Basically, anything you could grow or raise should be the main part of your diet.