Despite the bad rap that fats, in general, continue to receive, this macronutrient group plays an essential role in health and strength. In recent years, diets high in fat content have surfaced in popularity and controversy, including the keto, Banting, and low carb high fat (LCHF) diet plans, all of which are based on lowering carb intake, especially refined sugars and other carbohydrates, and increasing fat consumption to stimulate a ketogenic state.
Ketosis is a metabolic state whereby more of the body’s energy supply comes from ketones in the blood compared to glucose. In simpler terms, this means that low carbohydrate levels cause blood sugar levels to drop and the body begins breaking down fat to use as energy. Many experts say that ketosis itself is not necessarily harmful and can benefit overweight or obese people and those with type 2 diabetes.
The World Health Organization (WHO) recommends that less than 30% of an adult’s total energy intake comes from fats, with unsaturated fats preferable to saturated fats and avoiding trans fats found in processed and fast foods. Unsaturated fats are found in fish, avocado, nuts, sunflower, canola and olive oils.
Even more important, ideally, less than 5% of total energy intake should come from sugars, which are mostly added to foods or drinks by the manufacturer, cook or consumer but can also be found in sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.
In addition, there is an increasing buzz about the practice of intermittent fasting in advice and discussions about nutrition and dieting. All over social media, YouTube, and Kindle, it is allegedly one of the safest and fastest ways to shed fat if done correctly and works for most people. This is where, for example, a person refrains from eating from 7-8 pm and don’t eat their first meal until 12 pm the next day, thus fasting for about 15 hours each day, which allows for a drop of insulin levels, increase in human growth hormone, stimulating cellular repair processes, boosting metabolism, and reducing oxidative damage and inflammation in the body
But, more details about intermittent fasting in another article. For now, let’s look at some of the important functions that fats provide in nutrition.
1. Provide fuel for cells
Cells require a constant supply of energy to survive and generate and maintain their biological function. This energy is derived from the chemical bond energy in food molecules, which thereby serve as fuel for cells. As proponents of low-carb diets remind us, fat for fuel is actually preferred for human metabolism whereas an intake of processed grains and sugars are behind the skyrocketing obesity and diabetes rates.
At nine calories per gram, fat contains more than twice the number of calories per gram of carbs or protein, which have four calories per gram respectively, making fat the most energy-dense macronutrient. Also, fat does not require water for storage, as do carbohydrates, which means that water retention is less, and fat is a more efficient fuel than protein or carbohydrates.
3. Provide essential fatty acids
The two primary Essential Fatty Acids (EFAs) are known as linoleic acid (omega-6) and alpha-linolenic acid (omega-3) and are necessary for the formation of healthy cell membranes, healthy development and functioning of the brain and nervous system, proper thyroid and adrenal activity, hormone production, regulating blood pressure, liver function, immune and inflammatory responses, and the transport and breakdown of cholesterol, to name a few. For optimal health and performance, experts advise that one should consume a minimum of between 3% and 5% of calories from Omega-6 and about 0.5% to 1% from Omega-3 Fatty Acids. Fish, nuts, seeds, grains, legumes, and dairy are the main sources of EFAs.
4. Add as a carrier for fat soluble vitamins and antioxidants
The four important fat-soluble vitamins – A, D, E, and K – are required for a wide variety of physiological functions, including lowering the risk of cancer, type II diabetes, and a number of immune system disorders. Fats are needed to solubilize and transport these vitamins so that they can be properly metabolized, acting as chaperones in a way.
5. Insulate the body
In addition to storing and supplying energy in times of need, lipids make up the outer layer of all the cells and the fatty sheaths that insulate nerve fibers. Further, fat cells stored in adipose tissue, insulate the body and help sustain a normal core body temperature in cold conditions.
6. Act as an energy reserve
During sustained activity, when muscle glycogen reserves and blood glucose become depleted, stored fat in the body (in the form of triglycerides in adipose or fat tissue) is broken down into fatty acids that are transported through the blood to muscles for fuel.
7. Provide a protective layer for organs
Adipose tissue, or body fat, is a loose connective tissue that consists of two types, namely white adipose tissue (WAT), which stores energy, and brown adipose tissue (BAT), which generates body heat. Visceral fat is a white fat that develops around the organs, of which some is necessary to protect the organs from jarring and other forceful injuries.
8. Form brain tissues and nerves cell membranes
The balance of diet n-3 and n-6 polyunsaturated fatty acids (PUFAs) is the most important of brain tissue and membrane health in humans. Approximately 60% of your brain matter consists of fats that create all the cell membranes in your body. A diet that provides an appropriate balance of essential fats creates high-quality nerve cell membranes that function at their peak capacity. Further, omega-3 fatty acids support mental clarity, concentration, and focus.
So, how does fat intake relate to overall calorific requirements and common dietary advice? The National Health Service (NHS) suggests a need of 2,500 calories (about 10,500 kilojoules) for an average man to maintain weight and 2,000 for the average female (about 8,500 kilojoules). This increases to 50-80 calories per kilogram of bodyweight for strength athletes who participate in intense training. A deficit of 500 calories per day typically causes a loss of about one pound per week (half a kilogram). The widely accepted macronutrient ratio is 45-65% of carbohydrates and 10-35% protein. Professor Tim Noakes recommends eating no more than 100 grams of carbs per day on his low-carb high-fat (LCHF) Banting diet, which means getting only 400 calories from carbs, splitting the remaining need between protein and fat in a ratio that feels comfortable to the user and have the desired weight effect, keeping in mind that Banting is NOT a high protein diet.
Nevertheless, when one incorporates the recommended protein intake at between 1.2 and 2.0 grams per kilogram of body weight per day for athletes, which converts to about 450 calories per day for a 70 kg person. Discounting the calorific value of 100 grams of carbohydrates (400 calories) leaves A LOT of shortfalls to make up from fat. Sixty-five calories per kilogram body weight daily need for the same 70 kg athlete means a daily fat intake of more than 400 grams. This seems inordinately out of proportion and comments from proponents of LCHF diets are invited.
* Originally posted in http://www.powerliftingwp.co.za