The keto athlete and their dietary needsMark Evans PhD

Topics

• What is a ‘ketogenic diet’. How does it compare?

• Can it be used by athletes to improve their performance?

• What products are available to help individuals achieve/sustain ‘ketosis’

• Can these products help athletes improve their performance?

The Ketogenic Diet

Fat

Protein

Typical ‘Western’ diet

Carbohydrate

Fat

Protein55%

25%

20%

15%

80%

5%

Car

bs

(%)

Protein (%)

Protein g/kg BW

10%

20%

30%

40%

50%

60%

10% 20% 30% 40%

0.8 1.6 2.4 3.2

WFKD

Well formulated ketogenic dietCHO

Carbohydrate Loading

1g/kg

<50g

3g/kg

2g/kg

4g/kg

5g/kg

Medit

Mediterranean diet

WL

Weight Loss

Adapted from Virta Health

MG

Muscle Gain

Why use a ketogenic diet in sport?

= 300-500g of stored carbohydrate

= 100g of stored carbohydrate

1600 – 2400 total calories from carbohydrate

Stored fat in adipose tissue

Intramuscular fat

Circulating fat

10 kg total fat stores

90’000 calories of fat

CHO = 2000 kcal

“A clear quantification (or criterion) for successful keto-adaptation is still lacking. Various time durations have been empirically used in literatures to indicate keto-adaptation, generally referenced as short term (1–7 d), medium term (up to 60 d), and long-term (>60 d)”

Possibilities:

Levels of circulating ketone bodies

Increased fat oxidation during exercise

Hormonal responses

Evans et al. (2017) J Physiol

Burke. (2015)

Maintainance of submaximal exercise performance

<20g of carbohydrate per day for 28 days

Diet 85% fat

Ketone bodies > 1.0 mM

“....because muscle glycogen stores require many days for repletion, whereas even very lean individuals maintain appreciable caloric stores as fat, there is potential benefit in this keto-adapted state for athletes participating in prolonged endurance exercise over two or more days”

Burke. (2015)

Carbohydrate restriction = impaired use during high intensity exercise

Exogenous Ketone Supplements

AcAcDi-ester

1,3-Butanediol

βHB Monoester AcAc Diester βHB SaltsKetogenic Supplements

Cox et al. (2016)

Intermittent running performance

Evans et al., 2018

AcAcDi-ester

Leckey et al., 2017

“each of the riders nominated their gut symptoms asa distraction or interference to performance”

O’Malley et al., (2017)

*

Waldman et al. (2017)

Rodger et al. (2017)

Conclusion

• The ketogenic diet is a restrictive high fat, very low carbohydrate diet that requires a period of ‘adaptation’

• Athletes following a ketogenic diet can maintain low to moderate exercise capacity but the evidence shows an impairment of high intensity and intermittent performance

• Exogenous ketone supplements aid athletes to achieve acute nutritional ketosis, but there is limited evidence of a performance benefit