A Tale of Fat (or Lipids)

Whether you are diabetic or not, diet is important. What you eat matters in so many different ways, but it takes on even more meaning when a disease like diabetes develops. While carbohydrates and protein are significant for your body’s needs, so, too, is the much maligned fat.

Fats or Lipids – What are they?

The terms “fats” and “lipids” are essentially interchangeable. Only the context of usage is different. Fat is the word applied in general usage. Lipid is a medical and scientific term. Whether you refer to it as fat or as a lipid, it retains the same qualities and is characterized by its chemistry. Lipids consist of carbon, hydrogen and oxygen and are formed by fatty acids and glycerol. Lipids are not soluble in water and are referred to as insoluble. They are needed for energy storage.

The basis of a lipid is a fatty acid. The body cannot manufacture all of the fatty acids on its own; therefore, some are classified as essential fatty acids. There are two essential fatty acids that must be consumed in food: linoleic acid (omega-6 fatty acid) and alpha-linolenic acid (omega-3 fatty acid).

One of the critical fats that impacts health is saturated fat.

  • Saturated fatty acids – This form of fatty acids has carbon atoms that are “saturated” with as many hydrogen atoms as possible. Examples include palmitic and stearic fatty acids from plant and animal fat, and arachidonic from peanuts.
  • Unsaturated fatty acids – This type of fatty acid has a double bond. Examples are oleic group, linoleic and linolenic, vegetable oils, fish and nut oils.

Of particular concern to nutritionists is the industrial processing of unsaturated fats into the saturated state by adding hydrogen to liquid vegetable oils. These are called transfats.

What does Fat (Lipids) do?

The major role of fat in the body is energy storage. Lipids are a reserve source for energy rather than a resource that is instantly available such as glucose. In fact, a major portion of the body’s energy supply is stored as fat. It accounts for approximately 20% of the average body weight.

Fat is a concentrated source for energy in the form of calories. It does not matter what type of fat it is, it is still potential calories or energy. It is also an active participant in several cell functions. Lipids combine with other substances to:[1]

  • Form the cell membrane
  • Compose the myelin sheath – this white matter comprises the central nervous system (CNS) and lines the peripheral nerves
  • Act as part of the prostaglandin mechanism (fatty acid substances) in inflammation
  • Serve as a thermal insulator around various organs
  • Impact overall immune response

Lipid Biochemistry

It is important to understand the biochemistry of lipids if you are to understand its effect in such medical areas as diabetes, obesity and atherosclerosis.[2] Fat is insoluble, it does not dissolve in water. If fat is to be transported in and around the body in the blood stream, some changes have to occur. The solution is to associate the least soluble lipids with more soluble ones (phospholids) and then combine with a protein to create a water soluble lipoprotein complex.

The numerous lipoproteins are grouped by density for convenience. Since fat is lighter than water the lipoprotein is labeled low density indicating more fat. A high density lipoprotein indicates the presence of more protein in the make-up. The ranking of lipoproteins is as follows:

  • Chylomicrons are the least heavy and they transport dietary fat from the lining of the small intestine to enter the lymphatic drainage via the lacteals. They reach the liver after passing through the lymphatic channels and ducts.
  • Very Low Density (VLD) lipoproteins stand next in line or weight. Manufactured by the liver, these are the transport agents of those lipids intended to be deposited anywhere, for instance the adipocytes or fat cells waiting to be used as energy
  • Low Density (LDL) follows VLD in density level. This lipoprotein carries cholesterol, a necessary component in the formation of cell membranes. It also forms part of the multiple steroid hormones. When there is excessive cholesterol intake, it becomes LDL-cholesterol and can create medical issues. LDL-cholesterol may become deposited on the inner surface of the blood vessels. A build-up of this type can block them causing a coronary infarction. This is why dieticians and medical professionals refer to good and bad cholesterol.
  • High Density (HDL) lipoproteins are, as the name indicates the highest density. They comprise the good cholesterol. They are responsible for carrying any excess cholesterol back to the liver. The liver cells then break down the HDL before secreting it as bile.

Recommended Fat Intake

When you have diabetes or even prediabetes, you are at risk for having abnormal blood lipids. If this is the case, you will have to cut down your consumption of unhealthy fats.[3] The need to do so is also present if you are at risk for coronary heart disease (CHD). In terms of total caloric intake, the average person only requires 30% of their diet to be fat of all types.[4] Of this amount, your intake of saturated fat should count for less than 7% of your daily calories.

In order to keep your diabetes under control and prevent heightened risk for other health issues, including CHD, you should also

  • Minimize or avoid trans fats as much as possible
  • Lower your cholesterol intake to less than 200 mg a day

Conclusion

Whether you have or do not have diabetes, it is essential you monitor your fat intake. Keep your lipids undercotrol, including LDL cholesterol and triglycerides.[5] Take control of your diet. Watch the amount of fats you ingest daily. Talk to your doctor and a nutritionist to ensure you are eating right. Yet, no matter how you look at it, the rest is up to you. It is up to you to take control of your life, using your diet as a tool to help you seize control of your diabetes.

References

[1] Guyton, AC; and Hall, JE (2011). Textbook of Medical Physiology, 12th ed. Philadelphia: Saunders.

[2] Murray, R.K; Bender, DA; Botham, KM; Kennelly, PJ; Rodwell, VW; and Weil, PA (2009). Harper’s Illustrated Biochemistry 28th ed. New York: Lange McGraw Hill

[3] Warshaw, HS; and Pape, J (2009). Real-Life Guide To Diabetes. Alexandria, VA: ADA.

[4] American Diabetes Association (2009). Type 2 Diabetes. Your Healthy Living Guide. Alexandria, VA: ADA.

[5] Solano, MP; and Goldberg, RB (2006). “Lipid Management in Type 2 Diabetes.” Clinical Diabetes, 24 (1): 27-32.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.