#39 - Do keto diets and ketone supplements make sense for exercise and health with Dr Jonathan Little
Mar 18, 2023
auto_awesome
Dr Jonathan Little, expert on metabolism, nutrition, type two diabetes, and exercise discusses keto diets and ketone supplements. Topics include different types of keto diets, the rationale for them, their impact on health and exercise performance, adherence to keto diets, effect on body weight, controversies regarding cardiovascular risk, metabolic flexibility, and the relationship between keto diets and exercise metabolism/performance
Keto diets and ketone supplements have varying effects depending on factors such as weight, type 2 diabetes, and exercise type.
Keto diets are not superior to other diets for exercise performance, particularly at elite levels.
Keto diets may have some benefits for individuals with type 2 diabetes or those in ultra-endurance events, but they are not recommended for most athletes.
While low-carbohydrate diets may improve glucose tolerance and weight loss, more research is needed to understand their long-term effects on diabetic risks and complications.
Deep dives
Keto diets and ketone supplements: A nuanced approach
Keto diets and ketone supplements are a polarizing topic, with some people advocating for a low-carb, high-fat approach while others oppose it. The effectiveness of keto diets depends on various factors such as weight, type 2 diabetes, and exercise type. Keto diets have been used as a treatment for epilepsy, but the modern ketogenic diet is less extreme, consisting of low carbs, moderate protein, and high fat. Ketone supplements, ingested before exercise, are also discussed. However, studies show that keto diets are not superior to other diets for exercise performance, particularly at elite levels. Fat oxidation is not as efficient as carbohydrate oxidation, leading to higher oxygen consumption and lower power output during intense exercise. While keto diets may have some benefits for individuals with type 2 diabetes or those in ultra-endurance events, they are not recommended for most athletes.
The impact of keto diets on cardiovascular risk
Keto diets have been associated with changes in LDL cholesterol, with total levels often increasing while HDL levels also increase. However, the impact on cardiovascular risk is not clear. Some studies suggest that increased LDL particle size may mitigate negative effects, but this is not always the case. It is important to consider individual factors such as insulin sensitivity, weight loss, and metabolic adaptations. While keto diets may offer benefits for type 2 diabetes management, further research is needed to understand their long-term effects on cardiovascular health.
Keto diets and exercise performance
The concept of keto diets improving exercise performance is rooted in the idea of utilizing fat stores for energy instead of carbohydrates. However, the majority of research indicates that fat oxidation is less efficient than carbohydrate oxidation, leading to reduced power output and performance in high-intensity exercises. While there may be some benefits for ultra-endurance events, elite athletes have shown better performance with high-carbohydrate diets. Moderate carbohydrate intake and proper training are key for optimizing performance in most endurance sports.
Considerations for keto diets and health outcomes
While adhering to a keto diet may improve glucose tolerance and lead to weight loss, there is limited data on the long-term effects of keto diets on diabetes-related complications. The impact on micro and macrovascular complications is not well understood. It is important to balance the potential benefits of keto diets with considerations such as LDL cholesterol levels and individual health markers. More research is needed to fully examine the effects of keto diets on diabetic risks and complications.
Ketone supplements and ketogenic diets are not the same
Ketone supplements, such as beta-hydroxybutyrate, should not be considered as equivalent to a ketogenic diet. While ketone supplements provide an additional fuel source, they do not have the same metabolic impact as a ketogenic diet. Ketone supplements inhibit lipolysis, the breakdown of fats, and have minimal performance-enhancing effects in exercise.
Ketogenic diets may not optimize exercise performance
Contrary to popular belief, ketogenic diets are unlikely to improve exercise performance. While they can spare muscle glycogen and promote fat burning during exercise, they do not consistently lead to enhanced performance. Studies have not been able to replicate the initial positive findings, and optimal performance may require a combination of carbohydrates and other nutrients.
Low-carb diets may benefit some individuals
While there is no universally 'best' diet, low-carbohydrate diets might be beneficial for certain individuals. These diets have been shown to lower postprandial glucose spikes and improve glucose tolerance, particularly in individuals with overweight, obesity, or type 2 diabetes. However, more research is needed to fully understand the long-term effects and potential benefits of low-carb diets.
Dr Glenn McConell chats with Professor Jonathan Little from University of British Columbia. Kelowna, Canada. He is an expert on metabolism, nutrition, type two diabetes and exercise. We discussed what are keto (ketogenic) diets, different types of keto diets, the rationale for them and their effect on heath and exercise performance. We then did the same with ketone supplements. Whether there is a rationale for keto diets depends on who you are (overweight vs lean, insulin sensitive vs T2D, athletes vs non athlete etc).
0:00. Introduction and overview of the area
3:38. Jonathan’s academic and sporting background
6:58. Medical ketogenic “keto” diets and epilepsy
9:07. Modern “well formulated” keto diets and metabolism
13:15. What are ketone bodies
15:46. Ketosis and adherence to keto diets (and other diets)
20:04. Why/how keto diets reduce body weight
22:49. Are glucose excursions (spikes) a problem?
25:00. Effect of keto diets on cardiovascular risk/LDL etc
27:56. Keto diets when lean vs overweight or have type 2 diabetes
31:08. Cheat days when on keto diets
34:44. Metabolic flexibility/adapting to different diets
38:01. Keto diets and exercise metabolism/performance
43:10. Energy not produced as quickly from fat vs CHO
45:09. Endurance perf not better on keto diets vs high CHO diets
47:00. Controversies re keto diets and ex perf
49:25. Keto proponents arguments against high CHO
51:25. If not an elite athlete probably don’t need to pack in CHO
53:15. Keto may help overweight recreational sports people
54:26. Long term keto diets and health
57:07. CHO ingestion in keto adapted athletes
59:06. Very low RERs in keto adapted during intense exercise
1:02:30. Ketone supplements and exercise: types/rationale
1:04:58. Ketone supplements and exercise performance
1:07:58. Combined CHO plus ketone supplements and ex perf
1:09:13. Combined keto diet plus ketone supplements and ex perf
1:11:33. Ketone supplements and glucose tolerance/inflammation
1:15:01. Ketone supplements before and during exercise
1:15:58. Liver/beta cells and blood glucose regulation
1:18:12. Takeaway messages
1:23:23. Outro (9 secs)
Inside Exercise brings the who's who of research in exercise metabolism, exercise physiology and exercise’s effects on health. With scientific rigor, these researchers discuss popular exercise topics while providing practical strategies for all.
The interviewer, Emeritus Professor Glenn McConell, has an international research profile following 30 years of Exercise Metabolism research experience while at The University of Melbourne, Ball State University, Monash University, the University of Copenhagen and Victoria University.
