Little Byte Summary: Male athletes on a ketogenic diet observed body composition and testosterone changes compared to a control group on a different diet. Altering dietary carbohydrate intake seems to have a profound impact on mass and blood profiles in this group.
Background: We recently mentioned Prof. Jeff Volek and some ketogenic products in a post here. He continues to do cutting edge research, and recently measured the effects of reintroduction of carbohydrate on athletes previously on a ketogenic diet.
Here is a quote from his latest study (my emphasis KD = Ketogenic diet group):
Twenty-five college aged men were divided into a KD or traditional WD from weeks 1-10, with a reintroduction of carbohydrates from weeks 10-11, while participating in a resistance-training program. Body composition, strength, power, and blood lipid profiles were determined at week 0, 10 and 11. A comprehensive metabolic panel and testosterone levels were also measured at weeks 0 and 11…Lean body mass (LBM) increased in both KD and WD groups (2.4% and 4.4%, p<0.01) at week 10. However, only the KD group showed an increase in LBM between weeks 10-11 (4.8%, p<0.0001). Finally, fat mass decreased in both the KD group (-2.2 kg ± 1.2 kg) and WD groups (- 1.5 ± 1.6 kg). Strength and power increased to the same extent in the WD and KD conditions from weeks 1-11. No changes in any serum lipid measures occurred from weeks 1-10, however a rapid reintroduction of carbohydrate from weeks 10-11 raised plasma TG levels in the KD group. Total testosterone increased significantly from Weeks 0-11 in the KD diet (118 ng/dl) as compared to the WD (-36 ng/dl) from pre to post while insulin did not change.
What’s interesting to us is the that the reintroduction of carbohydrates continued muscle gain only in the ketogenic group. In other words, removing, then adding back carbs has an effect. The hormonal and lipid changes are also noteworthy.
More on this topic soon. We are starting to post on Twitter @bytenutrition