Ketogenic Diets

Q&A for Session #8
Jacob Mey, PhD, RD
Sports Nutrition Symposium 2.0
Thursday January 21st @7pm CST

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1. What criteria are used for measuring IR? If HOMA IR, what range do you consider healthy or high?
   1. HOMA IR is a measure of insulin resistance just from fasting measures. It’s an indirect measure of insulin sensitivity. Speaker generally does not prefer for research and prefers hyperinsulinemic/euglycemic clamp because it is the best, direct method, and is the gold standard. For insulin sensitive individuals (diabetic or metabolic disease) their glucose uptake is generally about 2 mg/kg/min. Really healthy individuals (athletes) have an uptake of 8-10 mg/kg/min.
2. What about sustainability? With my experience most people cannot sustain this diet very long?
   1. Most people the speaker has counseled last between 3 weeks-3 months on the ketogenic diet. It really depends on the person.
3. Any studies done on female participants, since their CHO metabolism differs than men?
   1. Great question. The primary institute that funds the speakers research, National Institute for Health, really wants the research to focus on having both males and females for obvious reasons. However, the older research has only included males previously. Therefore, there are some gaps in knowledge currently because of the lack of research, but hopefully in the near future these questions in regards to female specific research can be answered.
4. Could the endurance study be flawed due to the short term nature of the keto diet? Specifically I'm wondering if 6 days was enough time for an athlete to adjust to performing in ketosis without the chance to recover from "the carb flu" that is seen in the transition. Though it was in relation to the Paleo Diet, Dr. Lorraine Cordain recommended allowing an adjustment time of around 14 days.
   1. Yes, it is possible. Perhaps a longer utilization and time to adapt to the keto diet may have allowed the athletes more time to perform better.
5. Can you elaborate on the recent use of ketones by pro-cyclists, such as the highly successful Jumbo-Visma team?
   1. Speaker is not familiar.
6. Can you touch on Ketogenic diet and PCOS?
   1. PCOS is not a disease that the speaker typically reads about or focuses with his own personal research. However, PCOS is typical of poor metabolic health or poor glucose tolerance. So, providing a keto diet may improve metabolic health similar to what a diabetic would experience because with low carbohydrate intake there are less glycemic insults.
7. Are the ketogenic diets also calorie controlled? or is the focus just on the ketosis
   1. This will change study to study and depends on if the study controlled for calories.
8. What macro ratio are these studies using?
   1. They vary. PRO-15-20%, CHO- 5-15%, FATs finish out the rest. This is very generalized.
9. Do you know of any research done with keto diets and the military population?
   1. Speaker is not familiar with any research personally.
10. What are the potential long term effects on the liver of being on a ketogenic diet? Does it make a difference in the kind of fat?
    1. First thing that comes to mind is the reduction of fatty liver disease. The liver utilizes fat a lot more to increase the ketones to use for energy.
    2. In general if you ingest more omega 3’s or 6’s the cellular composition changes. It is unknown if it has the same effect on the liver.
11. What nutritional supplements would you recommend on a keto diet?
    1. It depends on the person. Basic multi-vitamin as a catch all. There are not real specific supplements that are recommended or work better or worse with the ketogenic diet.
12. What is the difference between using a ketogenic/low carb diet for fat loss versus becoming keto-adapted and using ketones vice CHO or body fat for energy? Thanks...great presentation!
    1. You are going to be having individuals use this in 2 different ways. #1- individuals are overweight or obese. Want to lose body weight. Their keto diet will put them in a calorie deficit. #2- athletes using it are not trying to lose weight they are trying to make sure they are fueling their body enough for exercise. They will be on an isocaloric diet.
    2. So the main difference is that if someone is looking to lose weight it is a keto diet paired with a calorie deficit.
    3. If someone is looking to utilize fats and ketone for performance it is typically going to be an isocaloric diet.
       What about the associated problems with KD like renal calculi etc. How are they dealt with?.
       Speaker is not a renal dietitian. Not sure on the ketogenic diet being used in individuals with renal disease. You have to be careful in this case, as you do not want to harm someone with this more complicated health issue.
13. Can you speak to the amount of weight loss seen when benefits of Keto were seen in both NAFLD and Type2 DM studies presented?
    1. The benefits you see are similar to any sort of diet you would see where it is a high CHO diet or a ketogenic diet. The weight loss is similar.
    2. It really depends on the study, how strict the calorie deficit is, and how long the study is.
    3. In general if you look over the course of a 12 week study, primary goal is to reduce body weight by 5-10%. Regardless of the diet we put individualize on, the main goal is to put an individual on a diet and help them lose weight by 5-10% of body weight.
14. A bit of a tangent from sports nutrition....what are your thoughts on keto diet for preserving brain health? Thanks for a great presentation!
    1. There is a lot of research interest in this area. Looking at ketones to preserve brain health or reduce damage from concussions, the thought behind this is that the brain can really primarily function when your metabolism is shifted. So if you change the nutrients available does this minimize damage and keep the brain healthier? There is more research needed here to fully understand. There is no concrete answer to this at this time.
15. Are there any differences between Ketogenic diets in type 1 and type 2 diabetes? You keep specifying type 2.
    1. He specifies T2DM, as this is primarily what he works with. Individuals experiencing T2DM are overweight or obese and this often comes from lifestyle of consuming excess sugar and calories, so that is is why he is referencing this more often. Whether it is type I or type II DM the point with ketogenic is to consume less CHO and therefore the thought is that it would be easier for the body to control blood sugar as a result. If someone is a T1DM or even T2DM that uses injectable insulin it is really key you talk to your physician about engaging in keto. They may need to adjust your insulin prescription, so you do not become hypoglycemic.
16. What about ketogenic & fiber/gut health/microbiome overall? Also, what about digestive issues for the athlete - any keto pro/cons related?
    1. Not quite sure. Like most things though, changing your diet will impact your microbiome. So a change is likely caused, but it is unsure if this is a positive or negative impact. The microbiome is very sensitive, so it probably changes but the impact on the body specifically is not clear.
17. How big of a role do you feel sodium intake plays in ketogenic diets?
    1. There is some thought that when you initially implement the ketogenic diet that the body is changing its electrolyte balance. He believes there are recommendations to increase salt at its initiation. He believes this is more antecedonal. Outside of the initial phase there is nothing in particular to sodium, rather intaking your normal range.
18. What kind of on-course nutrition strategy would an endurance athlete on a keto diet use?
    1. Unsure. His initial thought would be you would want CHO to utlizie this and perform faster. Perhaps MCTs could be used here, since they are shorter and the body can use these quickly. This is a thought, but there is no evidence behind this.
19. Do you recommend athletes to purchase ketone urine strips or blood ketone meters to monitor ketone levels?
    1. The blood ketone meters give a more precise measure. The urinary ketones typically have ranges and have a color scale with no number read out. He recommends the blood test via finger prick.
20. Can you clarify how to consider fiber in its carbohydrate contribution for a meal?
    1. Depends on what your goal is. If you are goal is to hit a certain CHO dose, then I would not count it as a part of your CHO macronutrients. However, if your goal is more calorie balance we do calories from these so he would include it. It depends on your main goal. Typically, he would say get the generally recommended amount of 25-30 g fiber per day.
    2. In terms of individual meals, he does not believe it matters too much.