The Nerdy Stuff with Kenneth Mao Part Three: Fat

Fat does not make you fat. Sugar makes you fat.

Fats, known chemically as the molecules triesters of glycerol (triglycerides) and fatty acids, are one of the three macronutrients (fats, carbohydrates, proteins). Fat is vital for body processes such as digestion, transport, conversion, and energy extraction. It’s our body’s primary source for stored energy, and by weight, it contains three times the amount of energy provided by glucose which must be provided to the brain in a continuous supply throughout the day. We can’t survive without fat.

Fat is necessary for many reasons.

• Digestion – Fat is not soluble in blood, so bile acids produced from cholesterol in the liver emulsify it along the way to make it bioavailable. It stores the fat-soluble vitamins A, D, E, and K in the liver and fatty tissues. Because fat needs to be broken down through multiple processes that include the stomach, duodenum, liver, gall bladder, pancreas, and small intestine, it stays around for a long time and keeps you satiated.
• Transport – Fat is part of every cell membrane in the body. It helps transport nutrients and metabolites across cell membranes.
• Conversion – Your body utilizes fat for everything from activating hormones to building immune function.
• Energy extraction – Between meals or when glucose is not available, triglycerides are broken down and metabolized for energy, which in times of great need, the brain’s neurons can utilize.
• Nervous system – The axon is the part of a nerve (neuron) that transmits electrical signals from the brain throughout the body to initiate all functions. The axon’s protective coating is the myelin sheath and is made of 80% lipids (fats) that must be provided by the diet.

Is it any wonder that the fat that composes our own bone marrow and most of our brain, saturated fat, should also be the fat that we consume?

Saturated fat has been demonized mainly because most sources are also high in cholesterol. Cholesterol is one of the most important constituents of life. Your body produces it and can regulate its levels whether it’s synthesizing its own cholesterol or cholesterol from dietary sources. Every cell needs it, the brain contains large amounts and cholesterol is the precursor to many of the most important hormones. In fact, a high saturated fat intake has been shown to reduce what we call the bad cholesterol, small particle LDL, and raise what’s called the good cholesterol, HDL. LDL and HDL are not cholesterol; they are transport lipoproteins, but the function of cholesterol and the way it works in the body, as well as what causes arterial plaque is misunderstood.

Most sources of natural saturated fat such as butter, lard and tallow contain high amounts of the fat-soluble vitamins A, D, E and K. Those vitamins need the presence of fat to be absorbed and are primordial for the absorption and proper utilization of other vitamins and minerals.

The air spaces in the lungs are coated with lung surfactant composed entirely of saturated fat. When the consumption of saturated fat is too low, the composition of this lung surfactant is compromised, and the lung’s air spaces can collapse. It’s possible that the proliferation of asthma in children and adults is due to a breakdown of this fatty layer.