 One of the biggest problems with the typical Western diet is the fact that much of our food is refined or highly processed. The refining process removes important nutrients like fiber, iron and B vitamins. And this is done by food manufacturers for two reasons. Firstly, it's to give the end product a softer texture. And secondly, it's done to extend the shelf life of the resulting product. A heavily processed food is going to last longer on the supermarket shelf because pests, like mold for example, are less attracted to foods that are low in nutrients. A hamburger that's highly processed will spoil much more slowly than a hamburger made at home with mostly natural ingredients. But the question is, if highly processed food is so low in nutrients that the pests don't even want to eat it, how healthy can it be for us? In fact, the nutrient content of any given food is directly related to the spoil rate of that food. Foods that are very low in nutrients spoil much more slowly than foods that are rich in nutrients. One of the best predictors of a healthy diet was whether it was cooked by a human being or a large corporation. And the reason is that when we outsource our food preparation to big companies, they tend to cook in a certain way that isn't very healthy. They tend to use way too much salt, fat and sugar, all of which are problematic nutrients for our health. And they tend to use the cheapest possible raw ingredients. Their business model is to start with the cheap food and process it as much as possible, make it attractive with salt, fat and sugar. Thinking about the nutrient density of a food is another conceptual way of making sensible food decisions. The nutrient density of a food can be thought of as the amount of nutritional value, including vitamins, minerals and fiber, divided by the calories or energy content of that food. For example, a glass of soda is high in calories without providing much in the way of nutritional value. Foods that provide lots of calories with very little nutritional value are sometimes called energy dense foods, but their nutrient density is low. A bunch of fresh spinach, on the other hand, would be an example of a nutrient dense food because its nutritional value is relatively high compared to its caloric content. When people talk about fast food being cheaper than fresh food, they're often referring to the fact that the cost per calorie of highly processed food is lower than that of fresh whole food. This is often true because highly processed food is so high in calories that the cost per calorie is relatively low. But if we instead look at the cost of food per unit of nutrient density, then buying fewer calories of higher nutrient density food is a much better use of our food budget. In the midst of a serious epidemic of obesity, avoiding empty calories should be near the very top of our list of priorities. One of the reasons why highly processed food is usually higher in calories is that in order to make these products sell, significant amounts of fat, sugar, and salt are added to make the nutrient stripped foods taste good. Additives like colorants, artificial flavors, stabilizers, and other preservatives are also added to enhance packaged products and maintain the illusion that we as consumers have many choices when we walk through the supermarket aisles. The last thing we need to be aware of are highly processed foods that masquerade as healthy foods. These are products that have synthetic nutrients added back to them after they've been refined, and this is usually done to make the product seem healthy to the nutrition aware consumer. It's important to remember that the most nutritious foods like broccoli don't come in packages that tell us how healthy they are.