A performance biochemist has said in a BBC article that Lewis Hamilton's shift to a plant-based diet could compromise his performance.
In a piece titled Lewis Hamilton: Could a vegan diet hamper his 'racing edge'?, Dr. Rob Child told news outlet BBC he believes it's 'a bad idea to switch mid-season'.
Child has previously worked with other drivers in Formula 1, as well as Tour de France cyclists and Olympic athletes, advising them on nutrition.
The biochemist believes diet changes should be made during the off season.
"Quite often changing a diet does throw up some issues that take some time to resolve. Ultimately during that period his performance could be compromised."
The doctor also mentioned the Formula 1 driver will have lower testosterone levels because of a vegan diet.
"This hormone contributes to aggression, which can be beneficial in racing and also helps muscle recovery and strength.
"A large drop in testosterone could reduce Lewis' 'racing edge' and could slow his recovery after training and races," says Child.
The biochemist also goes on to say the cholesterol found in saturated fat is 'important in the production of testosterone'.
Child also believes Hamilton will experience fatigue because of his diet change.
"It is very difficult to maintain body iron stores if you are a vegan athlete. Over the course of maybe a month, [iron and testosterone levels] could certainly drop in response to taking a vegan diet."
On the other side of the spectrum, the article also mentions former world number one snooker player Neil Robertson, who has been plant-based since 2014.
"Lewis Hamilton will benefit greatly, especially long term as well. It seems to be that athletes on a plant-based diet are extending their careers a lot longer than people would think," Robertson says.
"There are people in their 40s, 50s and even 60s doing things that they just shouldn't be able to do.
"It is really good of him to come out about it as well. When you have arguably the best F1 driver in the world advocating it and giving it a go it is great for everyone.
"He is inspirational and an idol to a lot of people."