Nutrition
What makes food healthy or unhealthy? Hopefully this page can clear up some misunderstandings.
Nutrients
Healthy eating involves keeping every nutrient within some optimal range
But it can be quite tedious to track every nutrient manually, so people typically rely on some sort of general food guide. By averaging enough different foods together, hopefully most nutrients will fall into their optimal ranges. But to really know for sure, you can check with the nutrition calculator (https://olam.wiki/nutrition.html).
Energy
The human body uses food as fuel.
This is measured in Calories (sometimes spelled "kalories" for disambiguation).
The word "energy" can feel a bit misleading here, because:
- It's easily confused with non-food energy, which this wiki also talks about.
- If you eat a high-calorie diet that is low in other nutrients, you will not feel energetic at all - you'll probably get fat.
- Some western diets fit this profile.
- The body needs other nutrients (especially vitamins) in order to burn calories.
- Body fat is extra calories stored, much like a gas tank of a car.
Food energy exists in a few forms:
- Carbohydrates (carbs) : 4 kalories per gram
(...)( Varies slightly - for example: sucrose has 3.88 kalories/gram; some complex carbohydrates have 4.11 kalories/gram. ) (...)( Includes sugars & starches (and fibre, although fibre can't be fully digested/absorbed). ) - Fats (oils) (lipids) : 9 kalories per gram
(...)( varies slightly ) - Protein (amino acids) : 4 kalories per gram
(...)( varies slightly )
The body can also burn a few other miscellaneous things, such as alcohol (7 kalories per gram).
Protein
The body needs a certain amount of protein, which typically accounts for about 10% to 25% of total calories. The rest can come from carbs and fats (the exact proportion of which doesn't matter too much).
Protein quality
There is a lot of confusing information about this, but it all boils down to:
- There is a recommended daily amount of total protein.
- There is also a recommended daily amount of each essential amino acid.
(see background knowledge)- Proteins are made of amino acids.
- There are about 20 different amino acids, 9 of which are essential.
- The body still needs the non-essential ones, but it can (if it needs to) convert essential amino acids into non-essential ones. The conversion can't go in the other direction.
It's not hard to meet both recommendations, just by eating a variety of proteins. A plant-based diet should generally include both grains and legumes.
Another factor in protein quality is digestibility, but this is not an issue if the food is cooked properly.
Fats
The body needs to eat some fat, for two reasons:
- To absorb fat-soluble vitamins (A, D, E, and K), these vitamins must be eaten with fat.
- There are essential fatty acids: omega-3 and omega-6.
For these 2 purposes, the amount of fat the body needs is fairly small - typically less than 10% of total calories.
Hence a healthy diet's protein/fat/carb ratio can vary widely and still be healthy. As long as you get enough protein and fat, the other 80% of calories can come from carbs, or more fats, or more protein (to a limited extent - too much protein can be hard on kidneys).
Fiber
Fiber is not absorbed by the body, but needed for healthy digestion.
Vitamins and minerals
It's important to get enough
Macro minerals (electrolytes):
- Potassium
- Chloride
- Sodium
- Calcium
- Phosphorous
- Magnesium
Trace minerals:
- Iron
- Zinc
- Manganese
- Copper
- Selenium
- Iodine
Vitamins: (wondering about missing letters?)Over the last century, some vitamins have been renamed; hence some numbers and letters are missing.
But this list is (hopefully) the full list of all known vitamins. If you think I missed any, please mention it in the discussion.
- A
- C (Ascorbic acid)
- D
- E (Tocopherols)
- K
- B1 (Thiamin)
- B2 (Riboflavin)
- B3 (Niacin)
- B5 (Pantothenate, or pantothenic acid)
- B6 (Pyridoxine)
- B7 (Biotin)
- B9 (Folate, or folic acid)
- B12 (Cobalamin)
Supplements
A daily multivitamin supplement can usually provide your full recommended daily intake of all vitamins and trace minerals - for quite cheaply (about 15 cents/day). But they can't provide enough of the macro minerals (electrolytes). That's because: if it did, the pill would be so big that you couldn't swallow it.
Hence you need to get most of your macro minerals from food - especially from vegetables and legumes.
There's a common misconception that "synthetic vitamins are useless, you have to get all your nutrients from food". That is not true.
But what is true, is that supplements can't completely replace food, for the reason mentioned.
One way to eat healthy is to eat the cheapest whole plant-based ingredients available, and take a multivitamin.
Choline
Scientists are still uncertain whether or not this nutrient is truly essential
Nutrient targets
This page is incomplete. This section will be filled in soon.
For easy tracking of nutrients, check out the nutrition calculator.
See also
- Food