As global obesity continues to rise; NH21 Weekly looked at the latest South African Demographic and Health Survey, which found almost 70% of local women are either overweight or obese. The country has the highest rates for women in Africa. (1)
According to the report’s co-author, Professor Alta Schutte;
“Excess body weight is a massive problem, but not only in adults. 13% of South African children are overweight or obese which is more than double the global average of 5%.”
She said this is of particular concern because children who are overweight have “little chance of being lean when they become adults”.
“If you are obese as a child the number of total fat cells in the body increases and stays the same when you get older. In lean children the number of fat cells is lower which gives them much better chances of remaining lean as they age.”
Make no mistake, this is not an issue of mere atheistic’s; excess weight is directly linked to the development of type-II diabetes, heart disease and cancer.
It is both alarming and reassuring at the same time, to consider that by simply following a seasonally variable, whole foods, plant based diet, this could all be avoided. Alas; for those who need reminding, an overview of “food” (as opposed to “products”) follows:
A food group is a classification of various foods based on the nutritional properties of each type and their principal effects on the body. Eating a certain amount from each group, and not exclusively avoiding any one, is recommended by most dietary guidelines in order to maintain a state of health.
The three basic groups are foods that provide energy, those of building and repair, and those that are protective and antioxidant. The components of food are divided up into the following categories:
The manner in which each person allocates these components in their diet depends greatly upon lifestyle factors including exercise and activity levels, and what they are hoping to achieve with their health. If the body does not receive the proper nutrients from food, normal physiological functions are impaired. But by choosing the healthiest forms of each nutrient, and eating them in the proper balance, the body is able to function at an optimal level.
The human body is roughly two-thirds water. Water is an essential nutrient involved in every single function of the body. It helps transport nutrients and waste products in and out of cells, and is necessary for all digestive, absorptive, circulatory and excretory functions, as well as for the utilization of water-soluble vitamins.
Consuming an adequate amount of water, whether through foods or fluids, is essential to maintain good health. If the body is sufficiently hydrated urine will usually be pale and odorless. Dark, strong smelling urine indicates dehydration and the need to drink more water.
Each day the body loses water through the kidneys, skin, lungs and feces. It is possible to get a portion of the daily intake required to replace these losses from fruits and vegetables; cucumbers for example, are roughly 90% water. However, obtaining proper fluid levels from drinking water and non-caffeinated herbal teas is preferable.
A carbohydrate is any one of a large group of compounds, including sugars, starches and cellulose; that contain carbon, hydrogen and oxygen. Carbohydrates are important as a source of energy; they are manufactured by plants when exposed to sunlight, and then obtained by animals (including humans) from the diet.
Honey is a rare example of a carbohydrate that seems to come from an animal i.e. bees. However, the sugars in honey are made by plants, and the bees simply collect and process them to produce honey.
Cellulose is said to be the most abundant molecule made by living organisms on Earth; so common because it forms the framework of the walls of all plant cells. Cellulose is composed of glucose molecules, linked together in long unbranched chains that pack closely together creating tough threads. Humans are not able to fully digest cellulose and it is known as fiber in the diet.
When plants have spare sugars, made in the process of photosynthesis, they store it as starch. Potatoes, for example, are tubers (roots) produced by the potato plant to survive the winter and be ready to generate new plants the following spring. Wheat and other cereal crops produce grains, their seeds for next year, containing starch.
The basic unit of a carbohydrate is a monosaccharide (single-sugar), of which glucose is the most important for the human body because our cells, especially those of the brain, use it as their primary energy source. All carbohydrates are eventually broken down by the body into glucose, which can then take part in energy-producing metabolic processes.
When we eat plants we break apart their starch to access the glucose within:
Starch + Water (saliva) → Glucose
Blood sugar, or glucose, can be obtained from either dietary sugar or dietary starch; but starch will be digested and absorbed into the bloodstream at a much slower rate than sugar. Starch is digested and absorbed over several hours whereas sugar may be absorbed in a matter of minutes.
Excess carbohydrate, not immediately required by the body, is stored in the liver and skeletal muscles in the form of glycogen, a polysaccharide (many-sugars). If a person consumes more calories than their body is using, a portion will also be stored in the body as fat.
Carbohydrates are divided into two groups; simple and complex. Simple carbohydrates, known as simple sugars, include fructose (from fruit), sucrose (table sugar), and lactose (from milk). Fresh, whole fruits are one of the richest forms of simple carbohydrate, with the addition of beneficial vitamins, minerals and phytochemicals; making them valuable for short-term, quick release energy needs.
Complex carbohydrates are also made of sugars, but their molecules are strung together to form longer, more complex chains. Complex carbohydrates, such as vegetables and whole grains, include dietary fiber, making them slower to digest and releasing sugar into the bloodstream at a steadier rate.
Proteins are large molecules composed of amino acids linked together by peptide bonds. They are essential constituents of the body, forming the structural material of muscles, organs, hormones and enzymes etc. While nutritional labels list ‘protein’ as though it were a single substance, there are thousands of different proteins in our food, and thousands in the human body.
When dietary protein is consumed the body breaks it down into amino acids, the building blocks of all proteins. Some of the amino acids are designated essential because they cannot be synthesized by the body and therefore must be obtained from the diet. Others are considered non-essential because, although they are required, the body is able to synthesize them itself.
Positive and negative charges at the ends of amino acid chains combine to form long strands that coil into extremely complex shapes; the end result being a protein molecule. Proteins can bond with other organic compounds to form ‘mixed’ molecules such as lipoproteins; water averse lipids attached to proteins that enable them to travel freely through bodily fluids.
The folded shape of a protein molecule determines its role in body chemistry. Structural proteins form essential structures such as collagen, a fibrous protein, that holds body tissues together. Functional proteins participate in chemical processes. These include certain hormones, cell membrane receptors, and enzymes.
Enzymes are functional proteins that work as chemical catalysts; they participate in chemical reactions but are not themselves changed by the reaction. Enzymes are vital to body chemistry as reactions would not transpire fast enough to be of use without them.
Whenever the body makes a new protein, for example building a new hormone, it needs a variety of amino acids. If there is a shortage of any one (i.e. through dietary insufficiency) construction of the new protein stops. The brain then triggers muscle cells to release their own stores to support the process of building vital new materials. In extreme cases (such as intense dieting or the eating disorder anorexia) this can lead to cachexia; a condition of severe muscle wasting, weight loss, fatigue and immune suppression.
Because of the importance of consuming proteins that provide all the essential amino acids; dietary proteins are grouped into two categories;
- Complete: containing all the essential amino acids.
- Incomplete: containing some, but not all, essential amino acids.
The biological value of a protein source describes how effectively body structures can be created from it after ingestion; depending on how closely its amino acid profile mirrors that of human tissue. The closer the match, the more biologically valuable a protein source is said to be.
Animal derived proteins have higher biological value than non-animal proteins; however, plant sources come in a healthier overall package that includes additional vitamins, minerals and trace elements. Also, whilst it is important to consume the full range of amino acids, it is not necessary to do so at every meal.
Combining several incomplete proteins, either in one meal or throughout the day, forms a complementary protein containing all the essential amino acids. Eating grains with legumes (e.g. rice and lentils), plus seeds and nuts, make high-quality substitutes for meat and can easily match the body’s protein requirements.
Protein is needed for growth and repair, but the average adult in western society consumes far too much animal protein. All animal products are acid forming. The body needs to neutralise the acidity in some way, and does so by creating a buffer. The main ingredient of this buffer system is the mineral calcium, which is obtained by leeching it from the teeth and bones, resulting in dental decay and osteoporosis.
Consuming excess animal protein also places stress on the kidneys. The breakdown of protein into amino acids releases nitrogen, which the body converts first into ammonia, and then urea to be expelled via the urinary system. Excess protein results in more highly concentrated urea which can lead to kidney stones.
Athletes and physically active individuals may need additional protein because they breakdown muscle tissue at a faster rate. If an active person gets inadequate protein from the diet it can lead to muscle degradation and lowered immunity. Should such a person decide to increase their protein consumption, especially from animal sources, alkaline foods such as fruits and vegetables should also be increased to balance acidity in the body.
FATS and OILS
Fat is the principle form in which the body stores energy. It also serves as insulation beneath the skin and around certain organs. The most common type of fat is a triglyceride; consisting of a single glycerol unit combined with three fatty acids. Triglycerides, which are synthesized from the digestion of dietary fat, are the form in which fat is transported in the bloodstream.
A noticeable characteristic of fats and oils is that they have a slippery texture and do not dissolve in water. In general, the term ‘fat’ is used to refer to those that are solid or semi-solid at room temperature (e.g. butter or cheese) and the word ‘oil’ to refer to those that are liquid at room temperature. However, the word ‘fat’ on a food label refers to both.
Dietary fat is necessary for the absorption of fat-soluble vitamins (A, D, E and K) from the intestine, and to provide essential fatty acids; a group of unsaturated fatty acids that are required for normal growth but which cannot be synthesized by the body. They belong to the groups Omega-3 and Omega-6 which include linoleic and linolenic acids. Essential fatty acids are components of cell membranes and help to regulate inflammation within the body.
There are three major categories of fatty acid; saturated, monounsaturated and polyunsaturated. These classifications are based on the number of hydrogen atoms in the chemical structure of a given molecule of fatty acid.
Saturated fatty acids are found primarily in animal products such as meat and dairy, but also some plant products including coconut oil. The carbon (C) ‘backbone’ is completely filled (saturated) with hydrogen (H) atoms, making the molecule straight and linear.
These molecules pack together neatly forming a hard fat, one that is relatively firm at room temperature e.g. butter. The liver uses saturated fats to produce cholesterol, which is an essential component of cell membranes. Most dietary information states that eating saturated fat can raise the level of cholesterol in the blood leading to hardening (and consequent loss of function) of these membranes; however, much recent work indicates that there may not be such a clear link as first believed, and that sugar is more likely to cause such a problem.
Regardless, one of the many risk factors for coronary heart diseases is an inappropriate ratio of different types of fats in the blood, including the two types of cholesterol known as HDL (high density lipoproteins) and LDL (low density lipoproteins). Yet many other lifestyle factors, such as stress, exercise and diets lacking in fiber, have broadened the understanding of what constitutes a risk factor.
What is not contested, is that for many reasons fatty deposits can build up on the inside walls of arteries and prevent the blood from flowing smoothly through the cardiovascular system. This is particularly problematic if the affected arteries are those supplying blood to the muscle fibers of the heart. If these get blocked there is a serious risk of a heart attack. Additionally, pieces of a fatty deposit can break off, leading to the formation of mobile blood clots which can lodge in the brain, cutting off the blood supply and causing a stroke.
One ‘problem’ is many people find that saturated fats taste good. Fried foods are extremely popular; but if too much fat is eaten, and the energy it contains is not used up in exercise, it can lead to ‘furred up’ arteries and obesity. When food manufacturers try to reduce the fat content of foods by producing low fat versions, people don’t tend to find them as appealing. The flavour is then ‘improved’ by adding sugar; meaning that many low fat foods have the same or more calories as the full fat versions.
Monounsaturated fatty acids are found mostly in vegetable, seed and nut oils including olive and macadamia. The carbon backbone has one (mono) double=bond resulting in two less hydrogen atoms and a slight kink in the molecular shape. These molecules do not pack together as neatly as their saturated equivalents, thus are less able to form solid structures; making them thick but not firm at room temperature. The fluidity of these molecules help to keep arteries supple. Monounsaturated fatty acids are found in the oils produced by our skin glands.
Polyunsaturated fatty acids are found in vegetable oils such as borage, hemp and evening primrose; and also in cold water fish. The carbon backbone has two or more (poly) double=bonds resulting in significant molecular kinks. These molecules do not pack together at all, making them extremely fluid at room temperature. Commonly termed ‘good fats’, polyunsaturated fatty acids have a natural tendency to disperse which helps the body to carry toxins to the skin, intestinal tract, kidneys and lungs where they can be safely discarded.
There is much scientific debate around the terms ‘good’ and ‘bad’ fat, specifically in comparison to sugar (‘worst’) and in relation to eating meat verses following a vegetarian lifestyle. All fats have important biological functions, yet each individual has a unique biochemistry, distinctive taste preferences and individual dietary needs.
During infancy fat is necessary for normal brain development. The myelin sheath of a nerve cell, for example, is a fatty substance that protects the delicate axons and increases the speed at which electrical impulses travel along nerve fibres. Fat provides energy and supports growth. If the body does not have adequate amounts of carbohydrate to catabolize, it shifts to fat to provide energy. Fat is the most energy dense of the macronutrients, yielding nine calories for every gram burned; twice that of carbohydrate and protein.
Archeological records and anthropological studies indicate that early humans were nomadic hunters and gatherers, following the herds and eating primarily nuts, berries, seasonal fruits and wild game. When agriculture was developed, a shift occurred from the wild and varied diet to one that included grain staples such as maize (a corn ancestor).
With this came the ability to keep grain reserves which in turn allowed cities to develop, social order to evolve, and a complex human culture and society to flourish.
With this also came a host of new gastrointestinal disorders. It is estimated that throughout human evolution the ratio of omega-6 to omega-3 would have been roughly one-to-one, as opposed to around 15:1 with today’s standard western diet; a dramatic shift that has been linked to more than simple gut pathology, but also chronic disorders such as heart disease, diabetes, arthritis and depression.
It seems clear that in terms of addressing these common health complaints, an increased consumption of unsaturated fats, and reduction of saturated fats, could benefit many people in modern society. In either case, the quality of dietary fats always outranks the quantity or type; and eating more dark green vegetables and less refined sugars would be even more important diet related health considerations.