What’s the best diet for you to eat? High-fat or low-fat? There is so much information about these suggesting one is better than the other, you may be confused regarding which one is better. I don’t blame you! But let me see if I can clear the air a bit by giving you some information to think on.

You may have been told to not eat a lot of fatty foods. If so, you’re not alone. Most nutritionists and government backed agencies have hammered into our brains the concept of “low-fat” is good. Manufacturers have picked up on this and now we have a plethora of foods that are low-fat. But is the low-fat diet the right diet to do?

For years I thought that low-fat was the way to go. However, my opinion about these was reversed when I read a study called the PREDIMET Trial.[1]The PREDIMET (Prevencion con Dieta Mediterranea) Trial was conducted in several countries in Europe involving thousands of people. They wanted to see if adding fatty foods to the Mediterranean diet would make a difference in the health of people.

A Mediterranean Diet is one of the best diets you can do to decrease your risks of developing heart (cardiovascular disease).[2]Many studies have made similar conclusions.[3],[4],[5]A Mediterranean diet emphasizes eating more seafood. All fish and seafood, including fatty fish, have been shown to decrease your risk of developing dementia, including Alzheimer’s disease. If you eat fish at least once a week, a study done in France demonstrated that your risk of Alzheimer’s disease can be reduced by 30%.[6]

The PREDIMET trial divided people living in different parts of Europe into three groups. All were told to eat a Mediterranean diet. Then they were told to vary this diet in one of three ways. One group ingested extra olive oil (50 cc/day more than what they normally did), another ate extra nuts (40 gm more of this fat-filled food on top of what they normally ate), and the third group ate a low-fat, but still a Mediterranean diet.

After five years, they had to stop the study because the results where overwhelming in favor of eating more fats. The results of the PREDIMET study showed a significant 30% reduction in cardiovascular disease in the oil supplemented group versus the low-fat group. Moreover, there was a significant reduction in total mortality, i.e. death rate, in the group supplemented with olive oil versus the control group.

In addition, a subgroup of people in the PREDIMET study also demonstrated a reduction in the risk of developing Type 2 Diabetes by a third (30% to 40%) in those ingesting the higher fats compared to those eating the low-fat diet. Diabetes is highly associated with developing heart disease, Alzheimer’s disease and dementia. Diabetics develop problems in their organs’ microvascular circulation, i.e. they don’t circulate blood adequately to the organs. An example you’ve probably heard of is diabetics developing ulcers of the skin. Heart and brain function may also be compromised due to this microvascular disease that occurs with diabetes. Thus, reducing the risk of this problem can give you improved heart function, brain function, and better quality of life by helping you think better.

In addition to these benefits, the higher fat diet group in the PREDIMET trial had a significant decrease in the risk of developing cancers. Breast cancer was reduced by 62% [7]Just doing a Mediterranean diet decreases breast cancer risk by 40%[8], but you can see that the higher fat Medi diet does better.

These and other studies changed my mind regarding low fat vs high fat diets. Thus, Low-fat is OUT! So, what about Ketogenic diets? They are high fat diets that put you into a state of ketosis, i.e. fat-burning mode. It so happens that ketogenic diets also decrease heart disease, decrease cancers, and decrease dementias, such as Alzheimer’s disease and Parkinson’s disease. [9]

These studies, plus many others, have provided us with overwhelming support for eating more fat that I thought: what about doing a diet that is a ketogenic diet, i.e. putting you into ketosis, but that emphasizes a more Mediterranean type diet, eating more fish, olives, olive oils, cheeses, nuts, vegetables and some fruits? Thus, I created my Keto-Medi diet protocol that we teach in our weight-loss program at our office.

You get the best of both worlds: a ketogenic diet that can help you lose weight and is healthy, plus a Mediterranean style diet with the health improving benefits of both. Both can help improve the health of your brain,[10]your heart[11], and the other organs of your body. Plus, a ketogenic diet may help treat or prevent diabetes and/or can reverse diabetes if you have it.

In conclusion, a high fat diet, i.e. a ketogenic diet, is good for your brain. But, combining a ketogenic diet with a Mediterranean Diet, or what I call a Keto-Medi diet may be even better. You thus get all the health-related benefits of both diets to help protect your brain and your heart. You get less cancers and your body is healthier with less dementia. If your heart health is improved, your overall health improves too because the heart pumps all nutrients to all parts of your body.


[1]Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med, April 2013;368(14):1279-1290 . DOI:10.1056/NEJMoa200303.

[2]IBID. Sofi F. https://doi.org/10.3945/ajcn.2010.29673

[3]Serra-Majem L, Roman B, Estruch R. Scientific evidence of interventions using the Mediterranean diet: a systematic review. Nutr Rev  2006;64:S27–47. https://doi.org/10.1111/j.1753-4887.2006.tb00232.x

[4]Sanchez-Tainta A, Estruch R, Bullo M, et al.  Adherence to a Mediterranean-type diet and reduced prevalence of clustered cardiovascular risk factors in a cohort of 3204 high-risk patients. Eur J Cardiovasc Prev Rehabil  2008;15:589–93. https://doi.org/10.1097/HJR.0b013e328308ba61

[5]Sofi F. The Mediterranean diet revisited: evidence of its effectiveness grows. Curr Opin Cardiol  2009;24:442–6.  doi: 10.1097/HCO.0b013e32832f056e

[6]Barberger-Gateau, et al. Fish, meat, and risk of dementia: cohort study. BMJ 2002; 325 doi: https://doi.org/10.1136/bmj.325.7370.932

[7]Toledo E, et al. Mediterranean Diet and Invasive Breast Cancer Risk Among Women at High Cardiovascular Risk in the PREDIMET Trial. JAMA Intern med. Nov 2015;175(11):1752-1760.

[8]Van den Brandt P, Schulpen M. Mediterranean diet adherence and risk of postmenopausal breast cancer: results of a cohort study and meta-analysis. Intern J Cancer Mar 2017. doi: 10.1002/ijc.30654

[9]Gosior M, Rogawski MA, Hartman AL. Neuroprotective and disease-modifying effects of the ketogenic diet. Behav Pharmacol. 2006 Sep; 17(5-6): 431–439. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2367001/

[10]McDonald TW, Cervenka MC. The Expanding Role of Ketogenic Diets in Adult Neurological Disorders.  Open Access. Brain Sci. 2018, 8(8), 148; doi:10.3390/brainsci8080148

[11]Han YM, et al. β-Hydroxybutyrate Prevents Vascular Senescence through hnRNP A1-Mediated Upregulation of Oct4. Mol Cell. 2018 Sep 20;71(6):1064-1078.e5. doi: 10.1016/j.molcel.2018.07.036