How Dietary Calories Get Converted to Energy
About 90% of the body’s ATP is generated in your mitochondria found in every living cell. Mitochondria are essentially your metabolic factories that maintain life. However, the constant generation of ATP to keep us alive creates a lot more heat than the body can handle so there is a constant need to dissipate that excess heat by evaporation through the skin. This is why you feel so miserable on a hot and humid day since it becomes very difficult to get rid of the excess heat generated by your mitochondria. The generation of ATP also produces excess free radicals in the process. Scientifically, this is called oxidative stress. Unless you have adequate levels of anti-oxidant enzymes in the body, those excess free radicals will start damaging tissue by increasing inflammation and making it far more difficult to repair damaged tissue. The more calories you consume at meal, the more oxidative stress you generate.
When it comes to generating ATP, you have two types of fuels: high-octane and low-octane. Consider the fatty acids found in the diet and stored as body fat as your high-octane fuel because you can generate a lot more ATP per gram of fat (i.e., high-octane fuel) than you can per gram of glucose (i.e., low-octane fuel). However, if you consume either potential fuel source (fat or glucose) in excess, whatever is not immediately used will ultimately be stored as excess body fat.
The absolute number of calories needed to make adequate levels of ATP depends on whether or not the body is using fat or glucose for fuel. One of the secrets of the Zone Pro-Resolution Nutrition system is that it allows you to consume the least number of calories yet produce adequate ATP that maintains your metabolism. This is the result of reducing insulin resistance in your fat cells, thereby allowing you to release more stored body fat as high-octane fuel burned by your mitochondria to produce ATP in other organs.
Maintaining adequate ATP production with the least number of dietary calories is only the first step in the Zone Pro-Resolution Nutrition system. You also have to ensure those calories also contain the essential nutrients that the body cannot make. The first three are the classical essential nutrients including (1) essential amino acids, (2) essential fatty acids and (3) vitamins. The other two classes of essential nutrients have only recently been investigated and can be considered as essential for the gut health. These include polyphenols and fermentable fiber that are both necessary for maintaining the health of complex ecosystem composed of trillions of bacteria in the gut as well as the human cells that line the gut wall.
Although dietary protein is a poor source to generate ATP, it is required to constantly synthesize enzymes, structural proteins (like hair, skin, and muscle), and proteins for the immune system. This enables you to maintain your muscle mass and immune system. Only nine of the twenty dietary amino acids are considered essential, meaning they cannot be made by the body and therefore must be supplied by the diet. High quality protein is defined as protein sources that supply adequate levels of those nine essential amino acids. The highest quality protein source is egg whites, followed by dairy protein because both are rich in essential amino acids. However, egg white protein has a much lower effect on insulin secretion than does dairy protein making it the best overall protein source. Without adequate levels of those essential amino acids, it is impossible to have efficient protein synthesis to maintain, let alone build, muscle mass, support adequate immune responses, or repair damage caused by cellular inflammation. Furthermore, adequate dietary protein at every meal is also required to release certain satiety hormones (PYY and GLP-1) from the gut that travel directly to the hypothalamus via the vagus nerve to reduce hunger so that you don’t over-consume calories.
There are two classes of fatty acids that constitute dietary fat. One class consists of essential omega-6 and omega-3 fatty acids that the body cannot synthesize and thus must be supplied by your diet because they are required to turn on and turn off inflammation and therefore. The other class consists of non-essential fatty acids (saturated and monounsaturated) that the body can synthesize.
You not only need both omega-6 and omega-3 fatty acids in your diet, but they must be in the correct balance to maintain a proper inflammatory response. Dietary intake of total essential fatty acids should have an approximate 2:1 ratio of omega-6 and omega-3 fatty acids. Today that ratio in Americans is about 20:1 of omega-6 fatty acids to omega-3 fatty acids. This mismatch generates an overproduction of pro-inflammatory eicosanoids.
Even though essential fatty acids are critical for life, the majority of your dietary fat intake consists of non-essential fatty acids, consisting of either saturated or monounsaturated fatty acids. These fats provide the materials for maintaining membrane structure and provide much of the fuel for ATP production. However, saturated fatty acids (especially palmitic acid) also stimulate inflammation, whereas monounsaturated are non-inflammatory. This is why you want most of incoming dietary fat to be consisting of monounsaturated fat. Olive oil, nuts, and avocados are great sources of monounsaturated fatty acids.
Vitamins are co-factors for a wide number of enzymes. Without adequate vitamin levels in the diet, enzymatic activity throughout the body will begin to slow decreasing the efficiency of your metabolism.
The need for vitamins was only discovered with the advent of food processing in the late 19th century that removed them from natural foods (such as removing the outer bran of brown rice to make more shelf-stable white rice). Only when vitamin deficiencies began to develop from the increased use of refined carbohydrates was it realized that something in natural foods (i.e. vitamins) were essential to human health. In fact, one of the sure pathways to winning a Nobel Prize in the early part of the 20th century was to discover a new vitamin. The richest source of vitamins with the least number of calories are non-starchy vegetables. These are also excellent sources of minerals so that if you are getting enough fermentable fiber, you are probably getting adequate levels of minerals.
In my opinion, polyphenols should also be considered essential nutrients since we now know they function as activators of various gene transcription factors critical for managing inflammation, metabolism, tissue repair, and the rate of aging as well as maintaining gut health. These essential nutrients are found primarily in non-starchy vegetables, fruits, legumes, and nuts. However, their naturally occurring concentration in these foods is low ranging from 0.1 to 0.2 percent of the total weight. Since your daily intake should be between 500 mg and 1,500 mg of polyphenols, this requires the consumption of large amounts of these foods. Since improved blood glucose control is another major goal for the Zone Pro-Resolution Nutrition system, the primary sources of polyphenols should come from low glycemic-load carbohydrates (such as non-starchy vegetables, fruits, nuts). This means consuming primarily non-starchy vegetables with limited amount of fruits or nuts. Although whole grains also contain polyphenols, they are considered high-glycemic load carbohydrates, since the entry rate of glucose from whole grain products into the blood is virtually the same as the same products made with refined carbohydrates. Thus, both refined and whole-grain carbohydrates generate an excessive insulin response that can rapidly drive down blood glucose levels leading to hunger and fatigue within a few hours after their consumption.
Fiber is also not currently considered an essential nutrient but it does contain a subclass of total fiber known as fermentable fiber. Fermentable fiber is an absolute requirement for maintaining a healthy gut. This is because the fermentation by-products of fermentable fiber (short-chain fatty acids or SCFA) are critical for maintaining gut health as I described earlier. The percentage of fermentable fiber in total fiber is highly variable ranging from zero in refined carbohydrates to nearly fifty percent in raw asparagus. I and most health authorities feel that you have to consume at least 30 grams of total fiber per day to provide adequate levels of fermentable fiber for the bacteria in your gut.
Theoretically there are no essential carbohydrates. However, the brain is the primary user of the body’s glucose intake as it consumes nearly twenty percent of the body’s total daily energy production even though it accounts for only two percent of your body’s weight. Unlike other organs that can use both fatty acids and glucose to produce ATP for energy, the brain can only use glucose. To produce that amount of energy the brain consumes much of the circulating blood glucose. Therefore, maintaining an adequate intake of dietary carbohydrates to maintain stable blood glucose levels is essential for optimal brain function. The brain requires about 130 grams of glucose per day. If you consume too few carbohydrates to maintain brain function, then the brain increases the secretion of the hormone cortisol that starts breaking down protein in your muscles to make glucose for the brain. This process is called neo-glucogenesis. On the other hand, if your carbohydrate intake is too high, then your pancreas secretes excessive levels of the hormone insulin that can accelerate cellular inflammation (especially in the presence of excess omega-6 fatty acids) as well as promoting the storage of excess carbohydrates as body fat (and primarily as palmitic acid). If you want to maintain an optimal metabolism, you also need to maintain a zone of carbohydrate intake.
Furthermore, there are also carbohydrate-containing glycoproteins and glycolipids that are critical for cellular signaling. These glycoproteins and glycolipids often contain unique carbohydrates (such as fucose, mannose, sialic acid, etc.) that theoretically can be synthesized by the body from glucose. However, if there is a defect in their synthesis then eating mushrooms or sea vegetables (primarily seaweeds) that are rich in those unique carbohydrates can help ensure that adequate levels of these specialized carbohydrates are maintained in the body.
The key factor of the Zone Diet is to obtain adequate levels of these essential nutrients with the least number of calories. At the same time, you need to eat enough calories to produce ATP, maintain stable blood glucose levels, manage inflammation and maintain the ongoing renewal process for the tissue in every organ. Beyond those levels, any excess incoming calories will be stored as body fat that can become a reservoir for the potential development of future diet-induced inflammation leading to the early development of chronic disease and accelerate the rate of aging.
Although it seems that balancing all of these nutrients with the least number of calories may seem difficult, following the Zone Diet makes it easy to adapt this as a life-long habit leading to a longer healthspan. This is why the first step to optimizing the Resolution Response starts with the Zone Diet.