Advice on diet and eating healthy.
First of all, I am not a nutritionist. I just read up a lot when I had leukemia about nutrition. This is generally what I learned. I wrote this originally to answer a question someone posed, but it got so long, I thought I should post it by itself to make it worth writing.

Most people who diet count calories but don't differentiate between the types of calories they consume in more than the most general sense. My advice is stop paying attention to calories and only pay attention to how much nutrition foods provide. A lot of calories, especially in America are mostly "empty calories", meaning that although they may provide energy, they don't provide any nutrients.

So, a calorie is a measure of heat. The measure of how much energy is needed to generate that measure of heat. Calories can be "empty" with no nutrients, or can be chock full of nutrients. and the energy levels will be the same either way.

Nutrients are the vitamins and minerals your body uses to build and maintain your body cells and functionality. A healthy diet is one that contains a wide variety of nutrients, the more variety the better.

Processed foods have a higher calorie count, and lower nutrient count. Avoid processed foods altogether. In some cases processed foods use up nutrients in order to be converted into energy (calories). As an example, natural sugars take about 2-4 chemical processes I order to be made useful. Processed sugars take 10-12 (or more) chemical steps to make useful. Those extra chemical steps use up nutrients that could be used to build and maintain your body.

Try to use as much food that is not processed and as close to its natural state as possible. Some foods are better absorbed after being cooked, while others are most nutrient rich if eaten raw. You will have to read up on your own about this because I am not about to write a while book here.

I find things from in our backyard, like tomatoes, are a lot more flavorful than store bought. As a general rule produce picked unripened and ripened artificially, has far fewer nutrients, than produce ripened on the plant.

Most vitamins and supplements aren't worth the money and some are outright junk. They will just drain out the next time you pee. Do research to make sure the brands you guy are actually in a form to be absorbed by your body. Use independent sources for research, not the brand names own website.

So-called "super foods" are great additions to eating a wide variety of foods to get a wide variety of nutrients, but don't rely on them as a solution to all your nutritional needs. Yes, they have a lot of nutrients, but they don't have all the nutrients you need.

Often neglected are "micro-nutrients", which are needed by our body only in very small amounts. If you eat a diet with a wide enough variety you will mostly likely cover these.
I ate vegetarian for several years while I had leukemia, for better health. If you don’t’ eat meat, you need to definitely have a very wide variety of foods, and my doctor recommended I take a B-complex supplement just to be sure I got enough B-12. In ancient Greece, the best Olympic athletes were all vegetarian. Be advised that as a vegetarian you will have to eat a larger volume of food and eat more often (I had to go from two to three meals a day).
Choose fresh produce first, and if not fresh then frozen.
Focus on keeping your food as natural as possible and the amount of nutrients the foods you eat have. If you body gets enough nutrients you may not feel hungry so often. For some people they feel hunger based on the nutrients their body is lacking. This is why people who eat junk food (empty calories, with no nutrients) are always hungry and eating, and why so many Americans are overweight.

Your body hungers for nutrients not calories.
Most processed food manufacturers have caught on to the three tastes the bodies craves. The body likes the taste of fat, sugar and salt. In nature (think in terms of hunter gatherer societies from which we evolved) those tastes helps the body get nutrients. In processed foods there are few if any nutrients, but the body still craves those tastes trying to get the nutrients it needs. So people who eat junk foods (or over processed foods) over eat because their body wants nutrients it isn’t getting, and so make you crave the flavors of sugar salt and fat, to get the nutrients it wants.