Nutrition and Food
Proper nutrition involves eating a healthy diet full of fresh fruits and vegetables, whole grains and unprocessed meats. Your body needs a balance of protein, fat and carbohydrates for energy and growth. In addition, there are a large number of essential vitamins, minerals and micronutrients your body needs that come from eating different varieties and types of foods. It sounds like it should be easy, but with the amount of processed and refined foods out there, it is becoming more difficult to make healthy choices without some guidance. There are many good diet plans out there but what must be remembered is that they should be used to jump-start healthier eating habits not merely for quick weight-loss. The ultimate goal should be a healthier you, not the temporary loss of a few pounds.
Diet plans which involve simply eating one or two foods while starving yourself of all else are the least helpful in this aspect. They may help you to lose a lot of weight quickly by inducing starvation while keeping you sated but they don't teach proper eating habits. In addition, your body misses out on the necessary vitamins and minerals for proper health. The ultimate goal is to teach yourself good eating habits so you can have the occasional treat without completely unbalancing you body's chemistry.
Other diets may restrict the intake of fats under the assumption that fat makes you gain weight. While it is true that fat has more calories per gram than both protein and carbohydrates, fats serve an important purpose in your body. They are use as a storehouse of energy to be used when instant energy isn't available and are also used as building blocks for cholesterol and many hormones. Diets that try to eliminate as much fat intake as possible are removing necessary fats as well as the unnecessary ones. A more appropriate method is to limit the intake of harmful fats, while maintaining essential fats in the diet.
There are several different kinds of fat which vary in quality and effectiveness in your body, unsaturated (polyunsaturated & monounsaturated) fats, saturated fats and trans-fats. Unsaturated fats are the easiest for your body to break down and utilize fully. These include the omega-3 and omega-6 fatty acids that you hear so much about. They have been shown to actually increase the levels of HDL (High density lipoproteins, sometimes referred to as "good" cholesterol) which can decrease the risk of atherosclerosis. They are found in fish, nuts, seeds, and vegetable oils. Saturated fats are not as easily broken down completely in your body and can lead to buildup of higher levels of LDLs (Low density lipoproteins, often referred to as "bad" cholesterol) leading to clogged arteries increasing risk of heart disease and stroke. These are primarily animal fats, found in meats and lard. Even worse are trans-fat which is unsaturated fat which has undergone a chemical process to hydrogenate it to make it solid but still soft. These are not easily metabolized by your body at all. They have been shown to cause an increase in LDL, a decrease in HDL and can contribute to coronary disease and type II diabetes. There are some sources of trans fats found in nature (lamb, beef, deer, buffalo, pomegranates, cabbage, peas) but these are minimal compared to that found in margarine, shortening, commercially baked goods, snack chips and frying oil.
A common fad today is diets which restrict carbohydrate intake. As carbohydrates are a good source of energy this eventually puts your body into a state of starvation. During starvation your body starts to breakdown the easy stores of energy first - proteins, which are found in large quantities in muscle tissue. If you are not constantly exercising and using those muscles, your body will take the easy way out and break down the proteins found there before working on fat stores. Your brain is capable using only 2 sources of energy for fuel, glucose & ketone bodies. Your body creates ketone bodies after breaking down proteins when there isn't enough glucose circulating. There has been shown to be a decrease in cognition with low carb diets, presumably because glucose functions as a better fuel source. During starvation, your body uses the proteins it has broken down to create ketone bodies for this fuel. Although there have been no studies linking a low carbohydrate diet to Alzeheimer's there is significant data linking a decrease in glucose over an extended period of time is a trigger for some forms of the disease.
As with fats there are both good and bad carbohydrates. Some carbohydrates are so refined and broken down that they shock your body into using them as soon as they are eaten. If your energy needs aren't high enough at that point in time, your body processes them and stores them in a form they can be used later. These are sugars, high fructose corn syrup and refined "white" grains (i.e. white flour, white rice). They should be minimized in your diet as they have been linked to diabetes, heart & kidney diseases, poor digestion and obesity to name a few. In addition sugar has been shown to suppress the immune system. A better choice is to consume more foods high in dietary fiber. These foods tend to be lower in calories as the fiber cannot be broken down, allowing the sensation of feeling full much sooner. A high fiber diet has also been shown to lower the risk of Type 2 diabetes, lower LDL levels, reduce inflammatory bowel diseases, reduce hypertension and reduce the incidence of some cancers of the breast and colon. This will help to avoid the tiredness and lethargy often felt after a meal high in refined carbohydrates. These foods are typically unrefined carbohydrates, such as whole grains, dried beans, some fruits and vegetables.