The word lipid refers to a broad category including fats, hormones, fat soluble vitamins A, D, E, and K, and more. Fat refers to a type of lipid called triglycerides including polyunsaturated fats, monounsaturated fats, saturated fats, and trans fats. Fats are important for energy production, immune support, regulating body temperature, insulating internal organs, signaling, and forming the structure of cell membranes (phospholipids). Fat plays a particularly important role in the brain, which is made up of about 60% fat.
Lipids refer to all types of fats, oils, and other related groups
Fat typically refers to a type of lipid called triglycerides (see below)
Lipids
There are many types of lipids in the body, here are some:
-Phospholipids (main part of cell membranes)
-Tri-glycerides (fat like body fat, animal fats, and oils), also di-glycerides and mono-glycerides
-Vitamins A, D, E, and K
-Certain hormones like cholesterol, testosterone, estrogen (these are all classed as steroids, which are a type of lipid)
Lipids are non-polar, and so don’t dissolve in water, which is important for many functions in the body. For instance, our cell membranes are made of lipids to keep the cell contents separate from what is outside of the cells by repelling the water in its surroundings. Also, fat soluble vitamins like A, D, E, and K are lipids, so they don’t dissolve in water, which is why you should consume fats with these vitamins to dissolve and absorb them [19].
Lipids are used by the body for energy production, immune support, regulating body temperature, maintaining skin and hair health, insulating internal organs, signaling, and forming the structure of cell membranes (phospholipids). Fat plays a particularly important role in the brain, which is made up of about 60% fat [88]. They also help with absorbing non-water soluble vitamins A, D, E, and K, which are lipids themselves.
[20][21]
Lipids include mono-glycerides, di-glycerides, tri-glycerides (fats), phospholipids (major part of cell membranes), waxes, sterols, steroids like cholesterol, testosterone and estrogen, and fat soluble vitamins (A, D, E, K) [22][23].
RDI
Dependent on the type of lipid, see below.
Deficiency
Dependent on the type of lipid, see below.
Toxicity
Dependent on the type of lipid, see below.
Triglycerides
Fats are composed of four molecules bonded together: 1 glycerol molecule, and 3 fatty acids.
Fatty Acids
-The terms saturated, polyunsaturated, monounsaturated, trans, omega-3 etc. all refer to fatty acids
-Only omega 3 and omega 6 fatty acids are essential, meaning they can’t be made in the body, but other types of fatty acids are likely still necessary for good health
-In order to make fat in the body, it joins 3 fatty acids with one glycerol molecule
-Fatty acids are a carboxyl group attached to a hydrocarbon chain that is either saturated, or unsaturated. Saturated chains only have single bonds, whereas unsaturated may have one or more double bond in the chain.
-Fatty acids are not found by themselves, but as part of triglycerides (fat), phospholipids, or cholesterol
RDI
78g [128]
Typically, 20 – 35% of total calories (for a 2000 cal diet, this is 44g – 77g) [119] are recommended to be obtained from fat, but this % is different for each person. Some perform well on very high fat diets, and others perform well with less.
Deficiency
Symptoms:
-Dry, scaly rash
-Frequent infections
-Slow wound healing
-Growth delay in infants and children
If no fats are consumed, biochemical signs show within 7 to 10 days [121].
Toxicity
Dependent on the type of fat, see below.
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