The Ketogenic Diet

Ok. So I keep hearing all about Keto-this, and Keto-that. What do I think?

I think it's a highly restrictive diet that has true medical benefits in a small number of people when supervised by a qualified professional. And let's be clear, I'm not talking about weight loss. The ketogenic diet was originally developed as a way to manage epilepsy in those for whom other methods hadn't worked. For those people, properly managed, it can be a huge help and increase their quality of life. There is mention that it may help with some forms of diabetes, but I do think more research needs to be done on that one. However, it's not without side-effects, which is why it needs to be monitored closely to ensure adequate nutrition. For all others? Sorry, but it's classified as a "fad diet".

I did an assignment on the ketogenic diet back in first year uni. So I thought I'd attach that here. Keep in mind, this was a short blog post-style comparison between a diet and the Australian Dietary Guidelines. But the research definitely played a part in forming my opinion on the diet.

As usual, the reference list will be included at the bottom.

The Ketogenic Diet

The Ketogenic Diet (“Keto”) is big at the moment with the popularity of the low-carb, high-fat (LCHF) movement. But what is the Ketogenic Diet? And how does it rate against the Australian Dietary Guidelines?

History of the Ketogenic Diet

Originally developed as a treatment for epilepsy and other neurodegenerative disorders1, Keto was adopted by the bodybuilding community in the 1980’s and 1990’s. With a promise of rapid weight-loss, it is popular in today’s health-obsessed society. While a LCHF diet may help with obesity and chronic conditions like Type 2 diabetes and polycystic ovarian syndrome2, more research is needed.

Keto Explained

Urbain et al. (2017) define Keto as very low in carbohydrates (<10% of total energy intake), and very high in fat (usually >60%).

The aim is to put the body into ketosis. In what Cox & Clarke (2014) describe as “an evolutionary adaptation… to sustain survival during famine, illness or energetic stress”, the body’s metabolism mimics that of one during a fasted state4. After a few days of restriction (“fasting” from carbohydrates), the body needs to find energy from an alternate source5. This comes from ketones formed from the incomplete breakdown of dietary fat4.

To achieve ketosis, dietary manipulation is required. In many cases, this means a lot of high-fat foods and removing any grains (or high-carb foods) and often dairy.

Foods to include	Foods to avoid
·     Small amount animal protein ·     Limited amount low-carb vegetables (leafy greens, cucumber etc) ·     High-fat foods (avocado, nuts, coconut, oils etc)	·     Root vegetables (potatoes, carrots etc) ·     Fruit ·     Most dairy (except butter and some cheeses) ·     Grains ·     Beans and legumes ·     Most processed foods

Keto vs the Australian Dietary Guidelines

How does this look against the Australian Dietary Guidelines (ADG)?

Using current scientific evidence, the ADG promote health and well-being and the reduction of chronic diseases6. There are 5 guidelines, but for this analysis the focus is on the first three:

1. Achieve and maintain a healthy weight, be physically active and choose nutritious food in amounts that meet your needs. 

2. Enjoy a wide variety from the 5 food groups – vegetables including beans & legumes, fruit, grains, lean meats & alternatives, dairy & alternatives – and lots of water! 

3. Limit intake of foods high in saturated fat, added salt, added sugars and alcohol.

On analysis, Keto doesn’t specify portion size or physical activity, and it is assumed that weight loss/maintenance is possible while on the diet. But defining ‘nutritious’ food is a major difference between the two.

Keto tends to remove fruit, grains, beans, legumes, most dairy and a few vegetables. With 4/5 food groups restricted, achieving Guideline 2 and Recommended Dietary Intakes (RDI) may be difficult. The high fat intake is also in contrast to what is advised in Guideline 3.

The potential for nutrient deficiencies and subsequent health issues is substantial. Hu & Bazzano (2014) note a lack of soluble fibre from wholegrains and fruits is concerning as is the amount of saturated fat, linked to cardiovascular disease. Other studies have recorded adverse effects which include amenorrhea and severe constipation8, kidney stones, anaemia, and high triglyceride levels9.

What does this all mean?

Keto is seen as a way to quickly lose weight, but Hall et al. (2016) suggest that fat loss is negligible between Keto and a higher-carb diet. (addition - I highly recommend reading this study)

While a moderate LCHF approach may show promise for some sections of the community, for the average person, Keto doesn’t seem advantageous. Current evidence suggests eating a variety of foods that suit your needs and personal preference. There is no reason to restrict entire food groups unless medically necessary, and in those cases, only with proper medical supervision.

References:

1. Scott-Dixon, K. & Kollias, H. (2016, August 15). The Ketogenic Diet: Does it live up to the hype? The pros, the cons, and the facts about this not-so-new diet craze [Blog post]. Retrieved from http://www.precisionnutrition.com/ketogenic-diet

2. Urbain, P., Strom, L., Morawski, L., Wehrle, A., Deibert, P, & Bertz, H. (Feb 20, 2017) Impact of a 6-week non-energy-restricted ketogenic diet on physical fitness, body composition and biochemical parameters in healthy adults. Nutrition & Metabolism, Vol.14(1) doi:10.1186/s12986-017-0175-5.

3. Cox, P.J. & Clarke, K. (2014). Acute nutritional ketosis: implications for exercise performance and metabolism. Extreme Physiology & Medicine, Vol.3, pp.17.

4. Whitney, E., Rolfes, S.R., Crowe, T., Cameron-Smith, D., & Walsh, A. (2017). Understanding Nutrition (3rd Australian and New Zealand ed.). South Melbourne, Vic.: Cengage Learning.

5. Paoli, A., Rubini, A., Volek, J.S., & Grimaldi, K.A. (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition Vol.67, pp.789–796, doi:10.1038/ejcn.2014.47.

6. National Health and Medical Research Council (2015). Australian Dietary Guidelines 1-5. Retrieved from https://www.eatforhealth.gov.au/guidelines/australian-dietary-guidelines-1-5

7. Hu, T., & Bazzano, L.A. (2014) The low-carbohydrate diet and cardiovascular risk factors: Evidence from epidemiologic studies. Nutrition, Metabolism & Cardiovascular Diseases, Vol.24, pp.337-343.

8. Sirven, J., Whedon, B., Caplan, D., Liporace, J., Glosser, D., O’Dwyer, J., & Sperling, M.R. (1999). The Ketogenic Diet for Intractable Epilepsy in Adults: Preliminary Results. Epilepsia, Vol.40(12), pp.1721-6, doi: 10.1111/j.1528-1157.1999.tb01589.x.

9. Kang, H.C., Chung, D.E., Kim, D.W., & Kim, H.D. (2004). Early- and Late-onset Complications of the Ketogenic Diet for Intractable Epilepsy. Epilepsia, Vol.45(9), pp.1116-23, doi: 10.1111/j.0013-9580.2004.10004.x

10. Hall, K.D., Chen, K.Y., Guo, J., Lam, Y.Y., Leibel, R.L., Mayer, L.E.S., Reitman, M.L., Rosenbaum, M., Smith, S.R., Walsh, B.T., & Ravussin, E. (2016) Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. The American Journal of Clinical Nutrition, Vol.104(2), pp.324-33, doi:10.3945/ajcn.116.133561