Low Fat or Low Carb?

It can be extremely confusing trying to decipher all the information regarding an optimal diet for a human being, let along one with insulin resistance (IR) or polycystic ovarian syndrome (PCOS).

Low fat? Low carb? How low?

A recent study published in the journal Lipids in 2008 described the findings of a group of researchers from the University of Connecticut who set out to find out what effects a carbohydrate restricted diet would have on the markers of metabolic syndrome (related to PCOS and IR) versus a low fat diet.

The researchers defined the carbohydrate restricted diet as being 1504 calories per day broken down into 12% of calories from carbohydrates, 59% of calories from fats and 28% of calories from protein.  The low fat diet was a little more restricted at 1478 calories of which 56% came from carbohydrates, 24% came from fat and 20% came from protein.

The study participants were both men and women who had ‘atherogenic dyslipidaemia’ or irregularities in their cholesterol and triglyceride levels and fatty acid ratios as is often the case in those with diseases related to insulin resistance – PCOS, Metabolic Syndrome, Diabetes Mellitus, Syndrome X etc.

The results of the 12 week study surprised many.  Whilst both diets improved the study participants laboratory test restults, those on the carbohydrate restricted diet had a much greater improvement.  They also had more greatly decreased levels of saturated fat in their blood, despite eating almost 3 times the amount of fat that those on the low fat diet did and lower levels of inflammatory markers such as TNF-alpha, IL-6, IL-8, MCP-1, E-selectin, I-CAM, and PAI-1.

The factors are all very relevant to the treatment of PCOS and decreasing the amount of inflammation in your body will have multiple benefits to your health both now and in the future.

An appropriate amount of healthy fats is an essential component of any healthy diet and I suspect that had the carbohydrate restricted diet been more carefully structured to include oils from sources such as Fish, Avocado, Olive, Coconut, Evening Primrose & Flaxseed and to exclude partially hydrogenated oils and trans-fats as well as saturated fats from non-organic meat, the results may have been even more impressive.

So in essence the message from this is:

  • Control your portions and limit calorie intake to an appropriate amount per day. 1500 calories is suitable for most sedentary or moderately active people trying to lose weight.
  • To reduce your risk of cardiovascular disease, limit your carbohydrate intake to 12-15% of your daily caloric intake and ensure that the majority of this is from low glycaemic index foods.
  • Don’t go overboard with fats – limit them to 40% of your daily caloric intake and ensure that they are from high quality ‘healthy fats’ such as oily fish (salmon, mackerel, trout), avocados and avocado oil, nuts and nut oils, coconut oil, olive oil, free-range organic eggs and poultry and organic grass-fed beef and lamb.
  • Eat plenty of high quality protein to help boost your metabolism and provide your body with the building blocks to repair and rebuild itself.

More Information:

Forsythe CE, Phinney SD, Fernandez ML, Quann EE, Wood RJ, Bibus DM, Kraemer WJ, Feinman RD, Volek JS. “Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation.” Lipids. 2008 Jan;43(1):65-77.

http://www.ncbi.nlm.nih.gov/pubmed/19082851

Kasim-Karakas SE, Tsodikov A, Singh U, Jialal I. “Responses of inflammatory markers to a low-fat, high-carbohydrate diet: effects of energy intake.” Am J Clin Nutr. 2006 Apr;83(4):774-9.

http://www.ncbi.nlm.nih.gov/pubmed/16600927

www.glycemicindex.com

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