Nutrition Overview: The Big Picture

There are literally thousands of books, magazines, and web- based resources  about food and nutrition – from textbooks and professional journals, to popular books and magazine articles. There is something for everyone’s level of interest.  While the span of available nutrition information is helpful the often conflicting messages presented in the media for public consumption, combined with the fragmented approach to nutrition (as well as medicine) leaves people with an incomplete picture about nutrition and food.  In addition to knowing the nutritional value of foods it is essential to also have an understanding of how food “behaves” in the body, i.e. what happens after you swallow – how what and when you eat affects your entire physiology from moods, sleep and energy to cravings and ability to achieve an appropriate body size; in other words, the “big picture”. If you would like to learn more – then grab your favorite beverage and read on…

Nutrients are basically divided into two groups: the large nutrients, called “macronutrients” and the small nutrients referred to as “micronutrients.” The macronutrients are proteins, fats and carbohydrates. These nutrients supply the body with energy and provide the raw material for building the body’s tissues and regulating many activities. The micronutrients are the vitamins and minerals. These nutrients do not provide energy directly; instead they facilitate the release of energy and participate in many essential daily activities.

Nutrients and Hormones – an overview

How the body handles nutrients, that is, whether the proteins, fats, and carbohydrates are used for energy and building blocks rather than converted into fat stores is regulated by hormones. Yes, those little chemical messengers we call hormones supervise what happens to the food after it is swallowed.

The key metabolic hormones involved in this conversation are insulin, glucagon, adrenaline, cortisol and a neurotransmitter (type of hormone) called serotonin.  Hormones regulate many processes including moods, energy, appetite, sleep, metabolism, and body size.  In other words they play a pivotal role in metabolism and nutrient supervision.

Insulin stows away nutrients in cells; its primary role is to regulate blood glucose levels (in concert with other hormones). Chronically high levels of insulin brought about by spikes in blood glucose are associated with a condition called insulin resistance which can lead to diabetes, hypertension, obesity, abnormal cholesterol and triglyceride levels, inflammatory disorders, accelerated aging, Alzheimer’s, memory loss, headaches, chronic fatigue – the list is practically endless.  High levels of insulin are implicated in most of the diseases mistakenly associated with aging.

Glucagon mobilizes nutrients. It works with insulin to regulate blood glucose and the distribution of nutrients. Glucagon tells the liver when to release stored glucose for brain and body fuel (for example low blood glucose level). Glucagon signals the cells to release fat for energy, and to release protein for building materials. The ratio between the two hormones insulin and glucagon determines whether food will be used as building materials and fuel, or stored away in the form of fat.

If the proportion of insulin to glucagon is high then food will be stored as fat. If the proportion of glucagon is higher, then food will be used as building materials and fuel.  Tempting as it may sound to want glucagon higher consider that over time, even a short time, if glucagon is constantly higher than insulin the net effect will be destruction of lean body mass because the body is constantly mobilizing nutrients. Glucagon is released in response to protein foods, whereas insulin is released in response to carbohydrates (and some proteins). If this is sounding a bit too “sciencey” and complicated -all it really means is that you cannot skip carbohydrates, as has been popular recently, and that protein should be included at each meal.

Adrenaline is a stress hormone; it is best known as the “fight or flight” hormone intended for high alert situations and for providing the body with fuel in emergency situations. So, just what is an “emergency situation”? Well, many years ago it was the appearance of a saber-tooth tiger.  These days we don’t see too many tigers in daily life; instead we have intense traffic conditions, deadlines at work, job and home and family stressors – our modern day life. Whatever the cause may be, the stress response is the same.

Adrenaline is also released in response to stimulants such as caffeine, tobacco, and drugs, as well as low blood glucose states often brought about from skipping meals. Although the adrenaline “high” can feel good to some people, it is a false energy. Eventually, this pattern of high adrenaline can lead to a feeling of “hitting the wall.” The “on the go” lifestyle that often includes skipping breakfast and going through to lunchtime on only caffeinated beverages, and sometimes even skipping lunch entirely, can lead to adrenal burn-out and muscle breakdown. This in turn slows down metabolism. A slow metabolism means weight gain. If all this sounds complicated, the bottom line here is do not skip meals, avoid too many stimulants, and seek out a practice to stay centered in the face of life’s stressors.

Cortisol is another major stress hormone. Living with long-term chronic stress contributes to higher cortisol levels. Alcohol consumption can also stimulate release of cortisol. Over time, high cortisol levels lead to fat gain and muscle loss. Again, cultivating perspectives to stay grounded and centered, i.e. manage stressors is central to good health.

Serotonin is a neurotransmitter, well known as the “feel good” hormone. Many things, not the least of which is stress, can influence serotonin levels. Low serotonin levels are commonly found in depression, obesity, diabetes, seasonal affective disorder as well as low estrogen states. Low serotonin levels result in low moods and contribute to carbohydrate and alcohol cravings (alcohol breaks down into sugar). The cravings are because sugar provides a temporary burst of serotonin to the brain and of course this feels wonderful. However, the feeling is short-lived. Once the brain level wears off, and it does so rapidly, the craving for more carbohydrates returns.  This is how people become stuck in the vicious cycle of carbohydrate cravings.  Understanding how the process works will help break the cycle. Avoiding blood glucose spikes is paramount to ending carbohydrate cravings as well as keeping moods on an even keel, and lowers potential for many (if not all) of the inflammatory health conditions prevalent today.

Believe in Balance – following an eating pattern that maintains hormonal balance is paramount to good health and easily done once you know the big picture and with a little practice.  Balanced hormones and balanced blood sugar keeps physiology in balance. It is much easier to improve habits and work on emotional aspects of eating once physiology is in balance. In terms of putting meals and snacks together there are just a couple more factors to consider.

Putting it All Together – Proteins, fats, and carbohydrates all digest at different rates.  This is important to keep in mind. A good way to remember is like this: proteins “walk”, fats “crawl” and carbohydrates “run”.  A carbohydrate eaten without any proteins or fats will “run” through the digestive process causing a rapid spike in blood glucose, which in turn causes a rapid spike in insulin which as you have read can lead to a host of problems – including weight gain, carb cravings, inflammatory responses, low energy and poor sleep. Need I say more?  This can be avoided by simply adding some protein and fat to the meal; and even further enhanced by adding non-starchy vegetables.  Unlike the starchy vegetables, the non-starchy vegetables are so low in carbohydrate content per typical serving size that they do not affect blood glucose much at all.  By including the proteins, fats and vegetables with the carbohydrate the entire meal digests slowly.

As the carbohydrates are delivered slowly into the digestive process they are more likely to be used for fuel rather than having to be rapidly processed and converted into fat storage.  This is analogous to putting twelve gallons of gas in a car – all the fuel cannot be used at once so it goes into storage until needed.  You want the fuel for your body to trickle in slowly so you burn it/use over the course of a few hours until your next meal.  Another benefit to balanced meals is that when digestion is slowed down, enzymes have more time to work on the food promoting better absorption.  Lastly, eating a meal that includes proteins, fats and carbohydrates is more satisfying and satiating and generally keeps hunger signals at bay for at least three to four hours, depending on the size of the meal.

Take Home Message – This eating pattern is simply a normal, healthy and balanced way of eating. It does not need a name given to it; however, you may consider it similar to a Mediterranean eating pattern, a low glycemic index eating pattern, or a low inflammatory diet.  I say, let go of all the names – play it down, we have developed an incredibly complicated, confusing and costly nutrition industry.  My bottom line – always eat real food, as whole as possible; include some proteins, fats, carbohydrates and non-starchy, colorful vegetables at each meal, and make sure portions are appropriate for your hunger level. Then, and perhaps the most important part – enjoy the meal!