"A healthy diet is one that helps maintain or improve general health. It is important for lowering many chronic health risks, such as obesity, heart disease, diabetes, hypertension and cancer. A healthy diet involves consuming appropriate amounts of all essential nutrients and an adequate amount of water. Nutrients can be obtained from many different foods, so there are numerous diets that may be considered healthy. A healthy diet needs to have a balance of macronutrients (fats, proteins, and carbohydrates), calories to support energy needs, and micronutrients to meet the needs for human nutrition without inducing toxicity or excessive weight gain from consuming excessive amounts."
Another Wikipedia article (here)says:
"Food provides nutrients from six broad classes: proteins, fats, carbohydrates, vitamins, dietary minerals, and water. Carbohydrates are metabolized to provide energy. Proteins provide amino acids, which are required for cell construction, especially for the construction of muscle cells. Essential fatty acids are required for brain and cell membrane construction. Vitamins and trace minerals helps to keep good electrolyte balance and are used for metabolic processes. Dietary fiber also affects one's health, although it's not digested into the body"
The problem with trying to define a healthy diet is that you have to define the goals for that diet, and everyone's goals will be different. For example:
My dietary goals are:
- (1) Avoid illness - that is, my diet should influence my body away from certain diseases - think diabetes, cancers, high blood pressure / cholesterol, etc.
- (2) Fitness - I need my diet to re-fuel my body, aid in recovery after exercise, provide proteins for building my muscles and carbs for fuelling my them.
- (3) Avoid fatigue - I have issues that I tend to be tired a lot, and my concentration and self-discipline are generally bad. I would like my diet to provide me with sustained energy throughout the day. This explains my fixation with low-GI meals.
- (4) Adventure / hobby - I like being a foodie. I enjoy learning to cook new foods and drinks. This obviously fairly radically effects the way I eat.
Disclaimer: I am a completely amateur nutritionist (not even close to a qualification), so what I think below probably doesn't count, but what I think w.r.t the above goals are:
(1) Avoiding illness - Eat lots of fruit and veggies. These contain all sorts of vitamins which are healthy. Also try to eat more unsaturated fats, which helps with cholesterol. Generally try to eat a broad assortment of things, so that your body isn't missing out on any nutrients, and don't eat too much of the same thing, so you body doesn't get overloaded with too much unhealthy stuff (think southern fried chicken).
(2) Fitness - Seems to come down to carbs and protein. Carbs provide glycogen for your muscles to operate, protein provides amino acids to build those muscles bigger. Make sure you have a decent amount of these inside of you before doing exercise, though not too much so that you get stomach cramps / stiches. And make sure you refuel on these things as soon as you're done exercising.
Water is also pretty important, to keep hydrated. And for those longs weekend runs or races - energy gels work wonders to top you up with carbs and to top up the electrolytes which leak out your skin when you run. Oddly enough you can eat salt when you run for the electrolyte thing, but my vote says energy gels are way tastier.
(3) Avoid fatigue - More to come on this later, because I'm pretty clueless right now. My best advice is aiming for a Low GI / complex carb type of diet which means you eat carbs which get absorbed slowly, so they're releasing energy slowly, so they release energy for a longer time, thereby giving you energy for longer.
Part in parcel with this is to eat more often. I find it pretty easy to eat at least 5 meals a day - the normal 3 plus a snack in between each, and then sometimes a snack either very early or very late, depending on whether I've worked out at these times or not. Exercise people say that all meals should contain both carbs and protein (to keep your muscles building themselves), but if you're just aiming for anti-fatigue food I'd say focus on the carbs. But also please note that carbs are what fruit and veggies are, not just wholewheat bread.
(4) Adventure / hobby - umm, you're joking right. Don't be afraid to cook something new. Favourite recipe website of the moment is Saveur.com , but there are many that I look at.
(5) Weight Loss - Calories, calories and calories. I am sorry that it seems to be this simple. Maybe there is a magic cure out there, and there certainly are certain things that help with burning fat, but really it comes down to eating less than you burn off. I recommend getting a lot of exercise to burn the calories off. I don't really recommend counting calories, but its probably worthwhile to know and think about rule-of-thumb calorie amounts. I'm not really qualified to talk about weight loss, I'm a skinny sh*t, so its never been important to me.
There are surely other dietary goals, maybe I'll get to them in the future.