Fats In Your Body: 20 Eye-opening Facts To Know




Fats In Your Body, With the popularity of low-fat diets for weight loss these days, it is helpful to look at the value (or otherwise) of fats in the diet.

Things aren’t what they seem. While low-fat diets may produce relatively quick weight loss, long term, they are not suitable for your overall health.

Fats (also called lipids) are essential for life as well as health.

In evolutionary terms, consuming good fats was critical for survival. They provided a long-term energy source and the essential components for bodily systems and the brain to function.

It has been suggested that the reasons our brains evolved in the way they did (the development of the large frontal lobe) was due to an increase in dietary fats,

particularly omega-3 fatty acids, from the food obtained from the watercourses beside which ancient humans lived.

Fats/lipids form the basis for hormones, brain activity, and antioxidant nutrients (vitamins A, E, D, K, and co-enzyme 010 are all lipids). These are all critical in the protection against degenerative disease.

Overeating fat can be a problem, but eating too little fat can be an even bigger problem.

Despite their poor image, fats are critical for health and survival. We need to make them sexier, so we know which fats to eat for optimal health (and the right amounts) without feeling guilty.

Knowing how fats work in the body will allow a person to determine a healthy amount — and which ones are important.

The primary consideration is not the amount of fat (within reason) but the type that determines our health or otherwise.

Although low-fat diets are promoted to reduce high cholesterol and heart disease, research indicates that the types of fat consumed have a more critical role in determining the risk of heart disease than the total amount.

Various clinical trials have shown that replacing saturated fat with unsaturated fat is more effective in lowering heart disease risk than simply reducing total fat consumption.

Research trials have provided strong evidence that an increased intake of omega-3 fatty acids from fish or plant sources substantially lowers cardiovascular mortality risk.

While dietary fat intake has declined over the years as a percentage of energy intake, the total caloric intake has not diminished. The prevalence of obesity and type 2 diabetes has grown dramatically.

Substituting fats with carbohydrates (sugars or excess fruit), as is common in low-fat diets, has been shown to increase the risk of degenerative diseases such as heart disease and metabolic syndrome (insulin resistance and diabetes).

Replacing saturated and trans-fats with unhydrogenated unsaturated fat effectively prevents degenerative disease than reducing overall fat intake.


The lipid family consists of a whole family of substances: for example, fats, oils, sterols or steroids (cholesterol, bile acids, hormones), phospholipids (lecithin),

fat-soluble vitamins A, E, D, K, and co-enzyme 010, waxes, neutral fats (triglycerides), fatty acids, glucolipids, sphingolipids.

These “fats” have many uses, including being concentrated sources of energy at 37kJ/g.

The lipid molecule is structured around carbon atoms, with hydrogen atoms attached to the carbon atoms in chains of varying lengths.

The number of hydrogen atoms attached to each carbon atom in the chains determines: (a) the degree of saturation (or unsaturation). More hydrogen means more excellent saturation.

(b) The fat’s melting point: unsaturated fats (oils) are liquid at room temperature, and saturated fats (like butter) are solid.

At a molecular level, saturated fats consist of a straight carbon chain with all the carbon bonds attached to a hydrogen atom.

Unsaturated fats contain at least one double bond, which is missing a hydrogen atom.

Monounsaturated fats have only one double bond (mono), whereas polyunsaturated fats have two or more double bonds (poly).

These double bonds are more unstable (to heat and light) than the single bonds to break down more quickly (oxidize) than saturated fats.

While polyunsaturated fats may have health benefits at some level, they can also be more damaging than other nutrients if they are rancid (oxidized).

Apart from heat and light, processing and cooking also oxidize fats. Double bonds are more fragile to oxidation than single bonds but are also more active metabolically.

While all dietary fats and oils contain varying amounts of saturated, monounsaturated, and polyunsaturated lipids, the predominant type determines its state (liquid or solid) at room temperature and its uses for humans.

Generally, most animals (including humans) store most of their lipids/fats as saturated, while most plants store most of their lipids/fats as unsaturated.

Therefore, saturated fats are generally animal fats. Monounsaturated fats are mainly olive Oil, peanut oil, grapeseed, and avocado Oil.

Canola oil has recently been added. These are more stable at high temperatures than polyunsaturates and therefore safer to use in cooking, but they are less stable at high temperatures than saturated fats.

Polyunsaturated fats such as vegetable oils or seed oils are safflower, sunflower, etc. These are less stable and, therefore, more likely to oxidize at high temperatures.

They can also contain the omega-6 (n-6) fatty acids and, in some cases, the omega-3 (n-3) fatty acids as well — for example, flaxseed oil and hemp oil.

They should never be used for cooking. The body differentiates between saturated or unsaturated fats in metabolic processes, saturated fats being used more for storage,

insulation or heat/energy production, while unsaturated fats are used more for structure, cell membrane maintenance, hormones, and metabolism.

The essential fatty acids, linoleic acid and linolenic acid are polyunsaturated fats. Linoleic acid (omega-6) and linolenic acid (omega-3) have a double bond on the sixth OT the third carbon from the methyl end, respectively.

This is how they are distinguished chemically.


Fats play a large number of critically important roles in the health and maintenance of body functions.

There are, therefore, several conditions that can result from diets too low in fat. The intake of fats/lipids will vary with climatic conditions and the type of occupation.

People who live in frigid climates may need a far greater intake than is considered ideal, as fats are required for body heat production.

However, for maximum nutritional benefits in a mainly warm country such as Australia, the fat intake should be about 20 percent of the total dietary intake (of the correct type of fats).

In Australia, the current intake of fats averages 50 percent and increases, mainly due to the increasing consumption of takeaway foods. Low-fat diets can be as low as 5-10 percent of the food eaten, which (over time) commonly leads to severe deficiencies of these fat-soluble nutrients.


For fats and lipids to support your health, the essential first step is the choices of dietary fats; the second is the correct digestion and then metabolism of these fats.

The process of digestion of fats is critically essential. To make sure these vital components of food are digested (and therefore in a form able to be used where needed), it is crucial to have several organs functioning optimally:

The liver 

The liver is vital to produce bile to emulsify the fats. The body is primarily made of water, and if you mix fat/ oil and water, fat floats — or, in this case, will be excreted.

Therefore, the fats will not be digested correctly if they are not made partially water-soluble — i.e., emulsified.

Bile, which is produced in the liver, ensures the fats are emulsified to be broken down by the (water-soluble) digestive enzymes called lipases (lipid enzymes).

The gallbladder 

When bile is made in the liver, it is sent to the gallbladder to store and concentrate.

When you eat fatty foods and hit the duodenum wall (just outside the stomach), a hormone called cholecystokinin (CCK) is produced that triggers.

• the gallbladder to secrete bile into the duodenum to emulsify the fats in the food;

• the satiety center in the brain tells you when you have eaten enough food and gives you the feeling of satiety (feeling full).

Eating fats in foods makes you feel full more quickly and can reduce the amounts you eat.

This process takes about 20 to 30 minutes so, by eating slowly and chewing food properly, you will feel full on less food.

Intestinal fat (fat from the diet) plays a significant role in appetite suppression and, therefore, in food intake regulation.

This is primarily due to the secretion of CCK as a critical physiological satiety hormone.

CCK functions as both a positive feedback signal to stimulate digestive processes (triggering the pancreas to secrete lipase to digest the fats) and a negative feedback signal to limit the amount of food consumed during an individual meal.

The pancreas 

Pancreatic lipase is the enzyme that digests fats. These are absorbed across the small intestinal wall and go to the liver and parts of the body where they are needed and metabolized.

Fats/lipids, once digested, are absorbed by two main routes. The short-chain fatty acids cross the intestinal wall and travel to the portal system, the liver’s blood supply.

A more complex process absorbs Longer-chain fatty acids and triglycerides with the formation of chylomicrons.

These are then absorbed through the intestinal epithelium into IIIa the lacteals (lymphatics). Chylomicrons (lipoproteins) are formed by the combination of triglycerides, cholesterol, protein, and phospholipids.

The phospholipid lecithin is the emulsifier that attaches the protein coat to the cholesterol to be transported.

These are absorbed through the intestinal walls via the lymphatic system, eventually flowing into the bloodstream at the root of the neck and finally traveling to the liver.

This latter is the primary route of fat absorption and transport. Chylomicrons are carriers of the fat-soluble vitamins in the blood, a linoleic acid source, and the primary form of triglycerides. 

Triglycerides are common in foods and can be formed from fatty acids or fructose, or glucose.

Excess fruit (fructose) and high-fructose sweeteners will raise triglycerides in low-fat diets.


Fat is not fat, and oils aren’t oils. The different types of fat vary chemically and therefore vary in their function and effects on your body.

• Mono-glycerides absorb across the intestinal mucosa with free fatty acids and go into the blood.

• Diglycerides are built into chylomicrons to travel to the liver via the lymphatics, then the bloodstream.

• Triglycerides are made of three fatty acids joined to a glycerol molecule. Dietary fats are 95 percent triglycerides.

Triglycerides are the storage form of lipids in adipose tissue. The body differentiates between triglycerides made of saturated or unsaturated fats or mixed fatty acids;

saturated triglycerides are used more for storage, insulation, and the production of heat/energy;

and unsaturated are used more for structure (including cell structure), cell membrane maintenance, hormones, and metabolism.

• Lecithin (a phospholipid) is manufactured at many sites in the body but can also be obtained from eggs and soybeans.

Lecithin is essential as a constituent of cells, particularly in the nervous system, where it constitutes the myelin sheath structure and forms the neurotransmitter acetylcholine in the junctions of nerve endings.

Lecithin assists bile acids as a fat emulsifier. Taken orally, this can be useful if there are problems with bile production or with gallbladder disease or removal.

Bile salts are composed partly of lecithin along with cholesterol and various nutrients. Lecithin is a principal constituent of cell membranes, and a phospholipid is responsible for the integrity and permeability of cell membranes.

If low in phospholipids, the cell membranes become “stiff,” altering the flow of nutrients into the cell and waste being excreted.

• Cholesterol is one of the sterols (steroid alcohols) and a significant precursor of steroid hormones. Cholesterol is found in all animal products but not in plants.

Saying a food contains no cholesterol only says the fats are not animal fats; it says nothing about the fat content of the food).

The liver is the primary site of lipid (cholesterol) metabolism. Cholesterol is also manufactured at various locations where it is needed: in the liver, small intestine, adrenals, gonads, skin, etc.

Despite its bad press, cholesterol is a critically essential nutrient. Dietary cholesterol is inversely proportional to body synthesis: the less we eat, the more we make.

The higher the saturated fat consumed, the greater the need for cholesterol (for chylomicron production).

Blood cholesterol does not necessarily reflect dietary cholesterol; instead, it demonstrates the cholesterol we have synthesized.

In our society, cholesterol problems tend to arise because of blockages in cholesterol metabolism-related to diet and metabolic issues (generally not the amount of cholesterol eaten except in very high-fat diets).

These blockages arise from:

• the increase in digestive and liver problems, which affects both the absorption and cholesterol metabolism.

• the lack of the appropriate nutrients to metabolize cholesterol correctly, such as choline, inositol, methionine, B vitamins, 1-carnitine, etc.

• a diet too high in refined carbohydrates and sugars (including fructose or fruit sugar). Fructose (fruit sugar) is particularly lipogenic (forms triglycerides); glucose is second.

Eating a low-fat diet tends to mean eating a higher-carbohydrate diet (i.e., the energy intake remains the same), and it is this that can raise triglycerides and cause “cholesterol problems.”

Those on a low-cholesterol diet frequently increase their fruit intake because it is assumed to be healthy (and it tastes sweet). This often raises triglycerides.

• the damage caused by chemicals and oxidized cholesterol to the liver (and artery walls).


Lipoproteins are made of fat and protein. The liver is the primary site of both fatty acid (lipoprotein) synthesis and oxidation.

When the chylomicrons from the small intestine reach the liver, they are broken down by lipoprotein lipase enzyme, which releases fatty acids and glycerol.

These fatty acids immediately diffuse into the fat in liver cells and are resynthesized into triglycerides. The significant lipoproteins are:

• Chylomicrons from the small intestine. These are lipoproteins of very low density and the largest of the lipoproteins.

Chylomicrons are the main transport form for triglycerides and fat-soluble vitamins to the liver. When the chylomicrons reach the liver, they are broken down by lipoprotein lipases, and the triglycerides, lecithin, and proteins are resynthesized into VLDLs (see below).

• VLDLs (very low-density lipoproteins) are primarily made of triglycerides and, as the body’s central triglyceride transport mechanism to the body, they supply triglycerides to produce the energy required for much of the body’s needs in the liver and muscles as well as for storage in fat tissue in the body.

Once the VLDLs have lost sufficient amounts of triglycerides, they are transported back to the liver and (with the action of lipoprotein lipase) are broken down and resynthesized into LDLs.

• LDLs (low-density lipoproteins) are the main cholesterol-carrying fraction of the lipoproteins, and they transport cholesterol to parts of the body where it is needed for metabolism.

LDLs carry cholesterol to the endocrine tissue to make steroid hormones (stress management and reproductive hormones), to the skin to make Vitamin D, to the nervous tissue for the manufacture of the myelin sheath, and the small intestine for chylomicron manufacture.

• HDLs (high-density lipoproteins). Once LDLs have discharged their cholesterol content, they are transported back to the liver and are resynthesized into HDLs.

These are proportionally richer in protein and phospholipids and lower in cholesterol, as most of the cholesterol and triglycerides have been deposited where needed in the body.

HDLs transport excess cholesterol away from the ovaries, adrenal glands, pituitary, and atheromas (in artery walls) and transport it back to the liver to be utilized to manufacture bile — thus completing the cycle (remember, bile is essential for fat digestion).

They are therefore considered protective for atherosclerosis and heart disease.


The standard medical cholesterol tests may not necessarily be an accurate indication for cardiovascular risk and are the subject of much debate these days.

In terms of cardiovascular disease, generally speaking, HDLs are considered protective (particularly HDL-2). In contrast, excess VLDLs and LDLs are considered damaging, not necessarily in themselves but in the fat-soluble chemicals and oxidized fats they can carry with them (combined with abnormalities in metabolism).

Therefore, to reduce the risk for cardiovascular disease, you need to encourage the production of HDLs and reduce the levels of triglycerides and LDLs.

To do this, you need to:

• reduce the levels of dietary triglycerides and trans-fatty adds (mainly) in the diet.

• reduce oxidized cholesterol by not overheating fats and not eating rancid fats. Taking vitamin E for its fat-soluble antioxidant effect helps. To reduce oxidized cholesterol, we also need the correct bacteria in the small intestine, good liver-detoxifying functions, and a conscious reduction in the exposure to chemicals in our environment and foods.

• have the right balance of fats in the diet, including sufficient n-3 fatty acids and good levels of fat-soluble antioxidant nutrients.

• reduce sugars in the diet, especially fructose.


The essential fatty acids are naturally occurring fatty acids that the body cannot synthesize. These fatty acids must be consumed in the diet.

There are two main types involved in the inflammatory pathways. These are linoleic acid — omega-6 (n-6) from land plants — and linolenic acid — omega-3 (n-3) from seafood.

These are considered anti-inflammatory. As arachidonic acid (considered inflammatory) can be synthesized in the body, it is no longer thought of as essential fatty acid. It comes mainly from animal products and excess or low metabolism of n-6 fatty acids.

There are also omega-9 (n-9) fatty acids, primarily oleic acid in olive Oil.

While n-9 fatty acids are not directly involved in the inflammatory pathways, they play a significant role in regulating their function.

Essential fatty acids are crucial substances for fine-tuning the body’s control system. Still, polyunsaturated fatty acids are easily oxidized or damaged by heat and light and can therefore go rancid quickly.

It is essential to consume them fresh and with vitamin E to help prevent oxidation. There is a role for both pro-and anti-inflammatory fatty acids in health. ‘

The balance is critical. The problem in the West is that we consume too few of the n-3 (omega-3) fatty acids, in particular, and an excess of the pro-inflammatory fatty acids (these days, it is more likely to be an excess of n-6 fatty acids), leading to a society prone to chronic degenerative inflammatory conditions.

An essential fatty acid deficiency can show up in almost all areas of the body with symptoms such as inflammation or chronic pain anywhere in the body,

mainly when parts of the body are “dry”: dandruff, dry skin, brittle nails, poor wound healing, dry eyes, poor vision (can also be vitamin A deficiency) and dry mouth (thirsty).

A common sign is goosebumps on the back of the upper arms, thighs, and buttocks.

Reproductive problems such as premenstrual syndrome (PMS), dysmenorrhoea, fatty degeneration of the liver with impaired cholesterol transport, mental disturbances (depression and ADD/ADHD in children, multiple sclerosis, etc.),

bronchial disorders such as asthma, bronchitis and dry, scaly inflammatory skin conditions such as eczema and psoriasis, as well as cardiovascular disease and the inflammatory autoimmune diseases, have all been associated with EFA deficiency.

Adults require approximately 20 percent EFAs (of fats) in their diet to replace an essential fatty acid deficiency.

Toxicity is unlikely as the EFAs break down to energy substrates. It was easier to get the n-3 fatty acids in the regular diet in traditional societies as meat (game) has about four percent fat, of which 18-20 percent is n-3 fatty acids.

Today, with the way we feed our animals, our meat is more likely to be 40 percent fat with little or no n-3 fatty acids. To change this, consume more (unturned) fish and game meats such as kangaroo.


Margarine and butter are common fats in our diets. Both have approximately the same amount of calories, but butter is slightly higher in saturated fats at eight grams than five grams.

Butter is a more natural product and is made from pasteurized cream. The water is removed, and it is churned until a solid.

The salt acts as a slight preservative and enhances the taste. However, organic unsalted butter is the best option as the starting materials are of better quality and it contains no salt, but it can go rancid quickly.

Adding wheat germ oil or the liquid from a vitamin E capsule makes the butter more spreadable, and 2000ius of vitamin E will also make it last longer without going rancid.

Eating butter has benefits in that it increases the absorption of many nutrients in other foods. Lipoprotein(a) is considered a more accurate genetic marker for cardiovascular risk than the lipoproteins usually tested medically.

An interesting study has been conducted, showing the stearic acid in butter may reduce the lipoprotein(a) marker greater than olive Oil.

The saturated fats in butter have been shown to improve the conversion of the omega-3 fatty acids into the active anti-inflammatory components EPA and DHA.

Margarine is a hydrogenated (manufactured) fat. Hydrogenation is when polyunsaturated oils are “saturated” with hydrogen, making them solid at room temperature.

The processing generates a high proportion of trans-fatty acids, which are biologically damaging to health.

These have been shown to increase total cholesterol and LDL while lowering HDL, lowering breast milk quality, decreasing the immune response, and affecting insulin response.

Many kinds of margarine these days claim to be trans-fat-free and indicate this on their packaging.

Still, if you want to maintain health, it’s best to avoid any hydrogenated fats, including margarine, even though they may spread more quickly.

Spreadability is only a convenience. For cooking, ghee (clarified butter) and copha (coconut) butter have higher melting points (more saturated) and will therefore not oxidize as quickly at high temperatures.


Unrefined cold-pressed oils are more likely to be the oils from straight crushing (rather than heating the seeds to make the Oil easier to obtain but risking increasing oxidation).

These are usually dark yellow with green haze (floating chlorophyll) with a strong taste and smell, but most of the nutrients are still intact.

Store in brown glass bottles away from heat. Do not store in plastic bottles or cans.

Polyunsaturated oils (sunflower, safflower, etc.). When purchasing omega-6 fats, always choose organic cold-pressed oils.

Do not cook with them as they oxidize quickly; use them sparingly. Excess polyunsaturated oils (particularly the omega-6 fatty acids) will have difficulty being metabolized by your body, and the excess is converted to inflammatory arachidonic acid.

This can contribute to the degenerative conditions associated with inflammation. Omega-3 fatty acids will compete for absorption.

Flaxseed oil has both n-3 and n-6 fatty acids (in a precursor form) but is not a cooking oil. It is highly unsaturated and very unstable to heat and light and will go rancid (oxidize) very quickly.

It can be challenging to metabolize in some people. Olive Oil is high in omega-9, which, while it doesn’t directly contribute to the inflammatory/anti-inflammatory pathways, helps balance high omega-6.

The main monounsaturated oils are olive, avocado, peanut, canola, and grapeseed. The best is olive Oil for general use, although it cannot be heated to the smoking point without oxidizing.

Use only cold-pressed, unrefined, extra-virgin organic olive oil.

There is extensive research on the Mediterranean diet’s health benefits, which primarily revolves around the quality of olive oil. 

Never overheat olive Oil. If frying with it, fry at a lower temperature. It has the lowest levels of trans-fatty acids at lower temps. It is the healthiest Oil to eat except when frying.

If you wish to deep-fry food, use rice bran oil with the highest conversion temperature — i.e., it will oxidize less readily at high temperatures.

Canola was initially genetically modified from rapeseed oil by removing/ reducing the erucic acid and calling it canola (from Canadian Oil, the company that perfected this process).

It converts to trans-fatty acids at relatively low temperatures, so it should not be used for cooking.

Canola oil is generally higher in the damaging trans-fatty acids due to the processing.


Trans-fatty acid consumption causes metabolic dysfunction: it adversely affects circulating lipid levels, triggers systemic inflammation, induces endothelial dysfunction, and, according to some studies, increases visceral adiposity, body weight, and insulin resistance.

Trans-fatty acids have a unique cardiometabolic imprint that is linked to insulin-resistance and metabolic-syndrome pathways, as well as the cell’s increasing inability to process insulin.

Consistent with these adverse physiological effects, even small amounts of trans-fatty acids (2 percent of total energy intake) are consistently associated with a markedly increased incidence of coronary heart disease and diabetes.

The ongoing Nurses’ Health Study of 80,000 women, conducted by Harvard Medical School and the Brigham and Women’s Hospital in Massachusetts, shows that for each 2 percent increase in calories from trans-fat, a woman’s coronary risk jumps by 93 percent.

Despite the drop in saturated fat intake by 10 percent across the board, diabetes rates and obesity have increased. Research suggests a significant problem may be the increase in trans-fatty acids in our diet.

Trans-fatty acids have been found in most margarine (at least in the past) and processed, convenient, and fast foods (french fries, fried chicken, doughnuts, pastries, cookies, crackers, and breakfast cereals) as they give flavor, crunch, and tenderness to pie.

Food manufacturers are researching new ways to deliver the taste people want in baked goods and snacks without using as much trans-fat.

Palm and coconut oils are coming into greater use as they have lower trans-fats.


Small amounts of butter may improve cardiovascular risk factors. Still, trans-fatty acids such as margarine and hydrogenated oils in processed and convenience foods and takeaway foods should be strictly avoided.

Olive Oil is suitable for general use but shouldn’t be overheated. It is excellent for salads and low-temperature cooking.

Make sure it’s extra-virgin, cold-pressed, and organic. There has been extensive research showing the protective role of olive oil in the Mediterranean diet. ‘

Extra-virgin olive oil has been shown to reduce several inflammatory markers, reduce oxidation and cardiovascular risk, and be even more beneficial if consumed from a younger age.

Consuming extra-virgin olive Oil may also help you lose weight. Rice bran oil is more stable than other oils and can be heated to much higher temperatures with minor damage.

It also has the advantage of assisting in the reduction of total cholesterol, LDLs, and triglycerides (although the HDL levels remain unchanged).

Flaxseed and hemp oils can be used for n-6 and n-3 supplementation for vegetarians but should never be heated.

Please make sure they are cold-pressed, organic, and fresh. For those wanting to lose weight, the good idea is to have a bowl of clear soup or a salad before a meal.

This is standard practice in France, and it results in approximately 12 percent fewer calories being eaten in any given meal.

The “French paradox” has created much discussion, with much lower cardiovascular disease levels despite high levels of saturated fats and red wine.

Explanations point to the straightforward soup/ salad mentioned above, along with the high levels of the antioxidant resveratrol in red wine.

Chewing food properly will also help as it also gets CCK and the satiety hormones working for you. Overall, fats and oils form a critically important part of our diet.

Low-fat diets are not suitable for your health long term. A moderate level of fat in the diet (20 percent; some say 30 percent) seems ideal, ensuring that a high percentage of these fats are n-3 (mainly), n-6, and n-9 fatty acids.

Also, ensure a high dose of the Overall, fats, and oils form a critically important part of our diet. Low-fat diets are not suitable for your health long term.

A moderate level of fat in the diet (20 percent; some say 30 percent) seems ideal, ensuring that a high percentage of these fats are n-3 (mainly), n-6, and n-9 fatty acids.

Also, ensure a high dose of fat-soluble nutrients such as vitamins A, D, E, K, and co-enzyme Q10 if you wish to maintain your health.

Supplementing with fish oil (and lecithin) and the fat-soluble nutrients can go a long way to achieving optimal health.