Max Petersen

endocrinologist, physiologist, track fan, dad

[Max Petersen @mpetersenmdphd]

@peasorpills Thanks! Participants had to eat our food, to maximize adherence to the protocol. Most did like the food, and our metabolic kitchen staff worked hard to prepare tasty entrees for all of the diets. A few did drop out in each group.

[Max Petersen @mpetersenmdphd]

1/11 Today our randomized clinical study is out in Cell Metabolism.
In metabolically unhealthy obesity, weight loss improved metabolic health on three very different diets. But when weight loss was matched, diet composition still mattered—especially for liver health. 🧵

[Max Petersen @mpetersenmdphd]

@exfatloss @TuckerGoodrich PUFA/SFA/MUFA as % of total energy, roughly, were: 13/23/37 for ketogenic, 7/8/20 for Mediterranean, and 5/3/7 for plant-forward. Omega 6/3 ratios were roughly 4.0, 5.7, and 4.7 respectively.

[Max Petersen @mpetersenmdphd]

Great discussion this morning about reasons for greater liver fat reduction with a ketogenic diet in our study. Some thoughts:

[Gil Carvalho MD PhD🌈🇵🇸 @NutritionMadeS3]

New RCT shows more liver fat loss on ketogenic diet vs Mediterranean and low fat plant based diets.

Genuinely interesting bc overall weight loss was similar and prior evidence indicated similar liver fat & visceral fat loss on high vs low carb
https://t.co/HwuUaGw3tS
(cont)

[Max Petersen @mpetersenmdphd]

@NutritionMadeS3 @TamarHaspel Not at this time (know anyone who'd fund such a study?) I agree it'd be interesting to run from a scientific/nutritional physiology perspective. Ketogenic diets do tend to be higher protein % than other diet patterns, though.

[Max Petersen @mpetersenmdphd]

@TamarHaspel @NutritionMadeS3 i) assessed in less than half of study participants; ii) assessed by using different methods during the duration of the study and not suitable for merging; iii) were not yet measured or analyzed; and/or iv) were beyond the scope of the present manuscript.

[Max Petersen @mpetersenmdphd]

@TamarHaspel @NutritionMadeS3 Of the 59 secondary outcomes in the registry, 26 pertain to the randomized trial presented in this manuscript. Of these 26 outcomes, those that are not reported in the present manuscript were:

[Max Petersen @mpetersenmdphd]

@BradChilmeran Good find, although they measured fasting glucagon and didn't quite reach statistical significance. Still, suggests lower glucose/insulin is a key driver of the higher glucagon on LC/keto.

[Max Petersen @mpetersenmdphd]

@tednaiman It's unlikely that protein explains all the diet differences we saw. I discussed possible mechanisms for greater liver fat reduction in the ketogenic diet group here: https://t.co/vIOb2ZmvZj

[Max Petersen @mpetersenmdphd]

Great discussion this morning about reasons for greater liver fat reduction with a ketogenic diet in our study. Some thoughts:

[Max Petersen @mpetersenmdphd]

@NutritionMadeS3 DNL is an important flux in MASLD. Newer studies using longer periods of deuterated water labeling have helped clarify this: https://t.co/XTC7d7YvAt https://t.co/7QoVcGbSBN

[Max Petersen @mpetersenmdphd]

@BluCheezWings Probably not without a low-insulin state.

[Max Petersen @mpetersenmdphd]

@NutritionMadeS3 Any time!

[Max Petersen @mpetersenmdphd]

Putting it all together: why did liver fat decrease most after the ketogenic diet? Despite greater dietary fat and NEFA delivery, reductions in DNL and increases in glucagon:insulin ratio and ketogenesis likely drove the result.

[Max Petersen @mpetersenmdphd]

Rounding out the fates of hepatic TG, VLDL-TG export was not directly measured, but fasting TG, VLDL size, and large VLDL particle count all decreased most on keto. This can be thought of as a response to lower liver fat, not a cause of it.