In some ways, this is not about what most people would call technology. However, the science behind nutrition is something that can be useful to all of us. There are a lot of people who do not understand just what is involved with "good nutrition" and they rely on aids, such as food pyramids, to attempt to create a good diet. However, understanding allows making better choices and knowing why we make those choices.
A healthy diet is composed of two factors -- calories and nutrition. On average, an adult needs approximately 15 calories per pound to maintain their weight. There's a lot of variation on this. Athletes and pregnant or lactating women need more. Sedentary people need less. But let's go with the 15 calories (actually kilocalories -- but most people just call them calories) per pound. This means that a 120 pound person (or someone who wants to get to 120 pounds) needs 1800 calories per day.
Calories are a measurement of the energy from food and, once again, it is simplified in presentation. A gram of fat is about 9 calories and a gram of protein or carbohydrates is about 4 calories. In general, it doesn't matter what kind of fat it is -- it will give you the same amount of calories. So, olive oil may contain "better" (from a nutritional point of view) calories but it will still be the same amount as that from lard. Proteins, once again, are all about the same for calories but the ability to be "burned" (metabolized) varies depending on the mixture of other foods with the protein.
At any rate, fats are the most calorie-dense foods at 9 calories per gram. This means that an average 120-pound person could get their daily calories from drinking 18 tablespoons (1 1/8 cups) of oil. They would also get severe diarrhea and eventually die of other causes -- but they would have enough calories. Prices of food vary around the world but, in the U.S., you can get canola oil at about $10 per gallon. There are 16 cups per gallon, so this amount of oil would cost about 70 cents.
At the high end of the scale -- I just don't know what that would be -- probably some rare gourmet low-calorie item. Let's just say that you can probably spend more than a $1000 for your 1800 calories. This is talking about actual base food costs -- eating at a restaurant would certainly increase your costs.
OK. We see that you can spend from 70 cents up to thousands of dollars to satisfy your caloric needs. But, we said at the beginning that a healthy diet is composed of calories AND nutrition. What is nutrition? These are the various components that your body needs to be as healthy as possible. It includes a proper balance of fats (and the right kinds of fats), protein (and the right kinds of protein), and carbohydrates (and the right kinds of carbohydrates). It also requires minerals, vitamins, and dietary fiber.
In the next post, I will start talking about the nutrition aspect of a healthy diet along with the economic impact of choices.
