W4-L4: Fats IV - Keto Flashcards
FUEL SELECTION: KETOGENIC DIET
What is the KETOGENIC DIET?
What are Ketones?
- Ketones: metabolic substrates produced in the liver in response to starvation / very low CHO intake
- Alternative energy source for various tissues, including brain
SAMPLE DAY
Ketogenic Diet
Is the Ketogenic Diet safe for everyone?
Not advisable for
* Those under18 without medical supervision
* Immunocompromised individuals
* Individuals with a history of an eating disorder
* People who have a history of poor discipline
* Athletes who are relying on high intensity effort for their sport
* in many cases a Mediterranean diet with a focus on less sugars and a calorie reduction may be the most sustainable & effective approach for weight loss
What are the Types of Ketone Bodies?
- Acetoacetate:
- first ketone body produced, which can be converted into the others (measured in urine)
- B-hydroxybutyrate:
- used as a primary energy source by tissues, including the brain (circulation + urine)
- Acetone:
- bby-product that is less commonly used for energy; it can be detected in breath and urine
What are the Ketone levels in blood?
Ketone levels in blood normally ~0.5mmol/L;
> 1 mmol/L indicates ketosis
What is Ketosis?
A normal metabolic state that occurs with a ketogenic diet or fasting, generally safe for healthy individuals
> 1 mmol/L indicates ketosis
What is Ketoacidosis?
A dangerous condition that can occur in uncontrolled diabetes, where ketone levels rise significantly, leading to a dangerous drop in blood pH.
What is the Body’s initial response to ketoses?
Initially
* ↓ circulating glucose, subsequently insulin ↓ allowing for increases mobilization of fat
* ↑ catecholamines (e.g. epinephrine) and cortisol = ↑ Glycogenolysis and Lipolysis
What is the Body’s response to ketoses after
2-3 days?
- ↑ gluconeogenesis from protein breakdown & glycerol from lipolysis
- liver glycogen stores are typically depleted after 2-3 days
- gluconeogenesis from protein is necessary, body will prioritize minimizing muscle loss by transitioning to ketones as the primary fuel source
What adaptations arise from a Keto Diet?
- Adaptation ~3 weeks – some people will adapt faster
- ↑ ketogenesis to provide fuel for brain. Can derive a significant portion of energy from ketones (up to 70% or more)
- Lipolysis continues - producing glycerol + fatty acids. Fatty acids can be used directly for energy or converted into ketones
- Gluconeogenesis continues - primarily from glycerol as ↓ rate of protein breakdown
- Thyroid hormone T3 falls = ↓ metabolic rate (a natural response as the body adjusts to a different metabolic state)
Keto Diet
WHO MIGHT IT BE BENEFICIAL
FOR? IF THEY ADHERE!
Individuals with Epilepsy
People with Obesity
Type 2 Diabetes Patients
Metabolic Syndrome
Polycystic Ovarian Syndrome (PCOS)
Fitness Enthusiasts
How would a keto diet help
Individuals with Epilepsy?
drug-resistant epilepsy - shown to significantly reduce seizure frequency and severity
Kossoff, E. H., & Turner, Z (2013)
How would a keto diet help
Individuals with Obesity?
can promote weight loss and fat loss, particularly visceral fat, by
reducing appetite and increasing fat oxidation.
Nordmann, A. J., et al. (2006)
How would a keto diet help
Individuals with Type 2 Diabetes?
may help improve blood sugar control and insulin sensitivity, leading to better management of diabetes.
Hu, T., et al. (2016)
Review Questions
