Recent research focuses on how environmental toxins, described as obesogens, are stored in fat tissue and can influence and interfere with healthy fat cell signaling and fat metabolism and how overeating can interfere with cell signaling messengers that control feelings of satiety after eating. For healthy fat metabolism, leptin, an adipocyte-derived hormone, plays an essential role in the maintenance of normal body weight and energy expenditure, as well as glucose homeostasis. Leptin resistance occurs in those who are chronically overweight. The role of leptin in the fat cells is to reduce appetite and stimulate fat burning. The relationship between leptin and perceived hunger, and on the eating behavior of leptin-deficient individuals appears to be blocked in chronically overweight individuals as they develop leptin resistance, making losing weight increasingly difficult, if not impossible.⁷

Fat also regulates the processes by which the body burns fuel for energy, especially in muscle. Adiponectin, another hormone-like chemical, plays a central role in the biology of fat and is normally produced to curb appetite and spark the burning of fat. But unlike leptin, which remains present but stops functioning, chronically overweight individuals have an adiponectin deficiency. Many adipokines are also mediators of inflammation and promote and encourage the inflammatory response, which further affects fat metabolism and homeostasis.⁸ Weight loss is associated with reduced inflammation systemically.⁹

Routine exposures to human-made chemicals may also increase an individual’s risk of obesity. The obesogen hypothesis proposes that perturbations in metabolic signaling that result from exposure to environmental chemicals known as endocrine disruptors, and stored in the body’s adipose tissue, may further exacerbate the effects of imbalances, resulting in an increased susceptibility to obesity and obesity-related disorders.¹⁰ These markers indicate the potential for nutritional coaching for behavioral change to improve metabolism, cellular communication, and promote long-term health.

Obesity is on the minds of health policy analysts and healthcare providers, nationally and globally. According to the CDC report, “Obesity is a complex problem that requires both personal and community action.” The report goes on to mandate that people in all communities should be able to make healthy choices.

From an evolutionary and cultural perspective, our modern-day food supply has been dramatically altered, although our biological nutrient needs have not. The human diet remained constant for thousands of years but has radically changed in the past few decades. It now becomes painfully clear that our modern dietary habits influence our health and well-being. For example, we know that food composition and macronutrient content are essential for biochemical processes, working synergistically to produce energy on a cellular level. Without proper nutrient synergy and healthy cellular communication, the end result is diminished function that often results in decreased energy output, inflammation, and lowered immune response. Essential macronutrients and micronutrients include carbohydrates, proteins, fats, vitamins, and minerals, and essential fatty acids.¹¹

© 2010 Integrative Nurse Coach Certificate Program (INCCP)

Carbohydrates provide the main source of energy for all body functions, aiding in digestion, assimilation, and metabolism of proteins and fats. Carbohydrates are classified as simple and complex. Simple carbohydrates include refined white flour products, white rice, white table sugar (dextrose), honey, fruit sugars (fructose), and milk sugars (lactose). Complex carbohydrates are found in whole grains, legumes, and vegetables and contain protein, vitamins, minerals, and fiber. Throughout human history foods that contain complex carbohydrates have been important diet staples in diverse cultures. Complex carbohydrates supply the body with essential nutrients and protein amino acids and provide longer-lasting energy than do simple carbohydrates.²⁰ All animal proteins are complete, including red meat, poultry, seafood, eggs, and dairy. Complete proteins can also be obtained through plant foods including soy, lentils, amaranth, buckwheat, and quinoa. Foods can be combined to make complete proteins like pairing beans with brown rice.

Dietary fiber is plant material that is left undigested after passing through the body’s digestive system. Fiber contains polysaccharides and can be subdivided into insoluble fiber and soluble fiber, each with a different mixture of compounds. Food sources of dietary fiber are often classified according to whether they contain predominantly soluble or insoluble fiber. Plant foods usually contain a combination of both types of fiber in varying degrees, according to the plant’s characteristics. Insoluble fiber includes pectin and cellulose, hemicellulose, and lignins.²¹ Insoluble fiber is present in fruits, leafy vegetables, whole grains and brans, and beans. Soluble fiber is a gelatin-like substance, such as the mucilage found in oatmeal and legumes.

Research clearly documents that the modern Western diet with its low fiber content has led to an increase in digestive problems, including diverticulitis, constipation, colon cancer, gallstone formation, and other gastrointestinal disturbances. Although dietary fiber is not digested, it increases fecal bulk and weight, making the passage of waste products more efficient and assisting in carrying toxins and metabolic byproducts through the intestines to be eliminated quickly from the system. Fiber also is important in modulating insulin response and thereby stabilizing blood glucose levels. In recent years, research into the benefits of dietary fiber has led many practitioners to recommend a low-fat, high-fiber diet for prevention of heart disease, diabetes, obesity, digestive disorders, and cancer.

According to Seymour Handler of the North Memorial Medical Center in Minneapolis, Minnesota, most of the serious diseases of the colon, including appendicitis and diverticular disease, can be linked etiologically to high levels of saturated fat and low levels of fiber in the Western diet. A diet high in saturated animal fat and low in fiber increases the risk of colon cancer. Guidelines for minimizing risk of colon cancer include reducing consumption of saturated fats and increasing consumption of fiber. Complex-carbohydrate foods offer fiber and are also good sources of protein, vitamins, and minerals.²² Fiber-rich diets help lower blood cholesterol levels and stabilize blood glucose levels and are considered heart healthy by multiple research studies. According to Dietary Guidelines for Americans 2010, at least half of all grains consumed daily should be whole and unrefined. The goal for fiber is 25 grams per day for women and 28 grams per day for men. Achieving these goals may reduce a person’s risk of dying from heart disease, infections, and respiratory diseases, according to a new study published in the Archives of Internal Medicine.²³

Protein is the second most plentiful substance in the body (after water) and constitutes approximately one-fifth of the body’s weight. Protein is the basic building block of the body and makes up the rigid structures such as bone, solid organs, and blood vessels. It is essential for the growth and maintenance of all body tissues, including muscle, skin, hair, nails, and eyes. Hormones, chemicals such as antibodies, and enzymes are composed of protein. Protein molecules, essentially composed of amino acids, form long chains and branched structures. Amino acids contain nitrogen, carbon, hydrogen, and sometimes sulfur. Twenty-two amino acids are required to build protein; half of these are produced in the body when adequate nutrients are available, and eight are considered essential.

Excessive protein consumption taxes the kidneys and digestive system. Because the majority of Americans consume most of their protein through animal products—a source of saturated fat as well—consumption of a large quantity of animal protein is associated with increased risk of cardiovascular disease and breast, colon, and prostate cancers. Plant foods such as whole grains, legumes, seeds, and nuts provide excellent protein, but this protein is incomplete, and these foods must be combined with others to provide all of the essential amino acids. Protein requirements depend on an individual’s activity level, energy requirements, age, and digestive health. The recommended protein allowance for health maintenance in the United States is 0.8 grams per kilogram of body weight per day. Men and women who body build require up to 1.2 grams per kilogram of body weight per day.²⁴

Lipids are a group of fats and fatlike substances, including essential fatty acids, that account for more than 10% of body weight in most adults. The principal function of fats is to serve as a source of energy. Stored fats also act as a thermal blanket, insulating the body and providing a protective cushion for many tissues and organs. According to the third National Health and Nutrition Examination Survey, Americans are eating less fat than they were 10 years ago. Americans now average 34% of their total daily calories (82 grams) from fat, with approximately 12% (29 grams) from saturated fats. Current dietary recommendations call for 20% of total calories from fat and less than 10% from saturated fats. The RDA for dietary fat suggested by the National Academy of Sciences to ensure the intake of essential fatty acids is 25 grams. Unsaturated fats are usually liquid at room temperature
and are derived from vegetables, nuts and seeds, soybeans, and olives. Saturated fats—found in animal products, including meat and dairy products —are generally associated with increased risk of cancer and cardiovascular disease. Foods often contain a mixture of saturated and unsaturated fatty acids. Fats are calorie rich and contain approximately 9 calories per gram, almost twice the calories of carbohydrates and proteins.

Essential fatty acids are found in both monosaturated and polyunsaturated fats. Monosaturated fats include olive, peanut, avocado, and canola oils. Polyunsaturated fats (PUFAs) are found in safflower, sunflower, corn, sesame, and soy oils. Fats can be further divided into two main classes: omega-3 fatty acids and omega-6 fatty acids. Essential fatty acids form a structural part of all cell membranes. They hold proteins in the membrane, maintain fluidity of the membrane, and create electrical potentials across the membrane, facilitating the generation of bioelectrical currents that transmit messages. Certain essential fatty acids substantially shorten the time required for the recovery of fatigued muscles after exercise by facilitating the conversion of lactic acid to water and carbon dioxide.²⁵ Essential fatty acids act as precursors for a family of hormone-like substances called prostaglandins, which regulate many functions in the body, including inflammatory processes and immune responses. Omega-3 essential fatty acids are immune enhancing and are often deficient in the modern diet. They contain high concentrations of linoleic acid and are necessary for normal growth and development throughout the life cycle. Omega-3 essential fatty acids are found in high concentrations in fish, fish oils, flax seeds, and walnuts. Research has shown that these essential fatty acids can lower blood pressure, lower cholesterol and triglyceride levels, and reduce the risk of heart disease and stroke. High concentrations of DHA are found in the brain, and a deficiency of this omega-3 essential fatty acid component can lead to impaired learning and decreased cognitive function. Other EFA deficiency symptoms include poor immune response, dry skin and hair, behavioral changes, menstrual irregularities, and arthritic and inflammatory conditions. Table 13-1 serves as a guide for general dietary goals and recommendations.²⁶