Intermittent fasting and keto promise similar metabolic benefits: enhanced fat burning, weight loss, better blood lipids (in some cases) But fasting days are brutal. Keto requires constant vigilance Researchers asked: What if it's the carb restriction, not calorie restriction,

The study: 12 healthy adults (avg age 27) tested 3 interventions in random order: -Normal diet: 55% carbs, normal calories -Low-carb normal calories: 50g carbs, same total calories -Low-carb restricted: 50g carbs, 75% fewer calories Then tracked metabolic response to high-fat

The triglyceride effect: Both low-carb groups had significantly reduced blood triglycerides after the test meal vs normal diet. The effect was the same whether they restricted calories or not. This suggests carb restriction itself drives the benefit /4

Enhanced fat burning: Respiratory quotient measurements confirmed both low-carb groups shifted more into fat-oxidation mode. The body literally switches fuel sources in just 36 hours of carb restriction, even while eating normal amounts of food /5

The trade-off: Post-meal glucose was temporarily higher after low-carb days (for the non-calorie restricted group). Interestingly, insulin levels didn't change. There was a reduction in GLP-1, which might have contributed /6

Although more research is needed to examine the long-term implications of increased glucose, research on cyclical keto suggests this normalizes with repeated cycles. It's adaptation, not dysfunction /7

Important caveats: Tested in healthy young adults for ONE day only Long-term effects of weekly cycling unknown The glucose effects need monitoring This is physiology, not proven clinical outcomes and more research is needed /8

Overall, these results suggest a single strategic low-carb day might offer an elegant compromise between the extremes of full keto and fasting, potentially making metabolic optimization through diet more accessible. Full breakdown in my weekly newsletter./9

@BrandonLuuMD In other words "restrict calories".👍

@BrandonLuuMD Mechanistic speculations on 1 day... If only we had RCTs to show long term hard outcomes. Life is too short for restrictive diets. Especially since excellent health outcomes are achieved with energy deficit and ultimately, long term energy balance on diets with mix of macros.

@BrandonLuuMD Makes sense! Not eating carbs is just like not eating!!

@BrandonLuuMD There was an RCT on low carb diet over a decade back, it showed that it mimics fasting, isn’t this confirms that but on single day time scale.

@BrandonLuuMD Super interesting 👀 Carb restriction flipping the same metabolic switches as fasting—without the full fast. 🚦 But curious what the “catch” is… sustainability? insulin dynamics?

@BrandonLuuMD That's a fascinating premise, Brandon. The connection between carbohydrate restriction and metabolic benefits typically attributed to fasting could indeed have significant implications for dietary strategies. I'm curious about the "catch" you mentioned—does it relate to

@BrandonLuuMD Looks like even one low-carb day can shift our bodies into fat-burning mode and lower triglycerides, without cutting calories. Still, this was only tested short-term in healthy young adults, so the long-term effects aren’t clear yet.

@BrandonLuuMD Didn’t they do a study on different intermittent fasting methods and found caloric restriction to be the most effective?

@BrandonLuuMD Fascinating breakdown, Dr. Luu. The idea that a single low-carb day could mimic fasting benefits, without the misery, is a game changer.

@BrandonLuuMD 🚨 An Indian plate of "balanced diet" looks like 50-60% of carbs ; 10-15% of protein; and 20-30% of fats. This is disaster, because I think atleast 35% protein is important. A Report say 80% of Indians are protein-deficient.

@BrandonLuuMD would this qualify as data - many indians fast 24 hours on the waxing/waning 11th day - thats 2 days a month and 24 days a year - some dont consume water as well for nearly 24-36 hours

@BrandonLuuMD You don't even need calorie restriction to improve metabolic health with a short term low carb diet. A eucaloric low carb diet, but not a eucaloric low fat diet, reduced liver fat in a crossover RCT. Reducing liver fat has big implications for t2d https://ajcn.nutrition.org/art...

@BrandonLuuMD Interesting findings carb restriction alone may mimic fasting benefits, though context and balance matter.

@BrandonLuuMD Healthy eating does need more promotion and i'm doing my best to do so https://x.com/workwithnature1/...

@BrandonLuuMD @Grok. summarize this thread, please.

@BrandonLuuMD @threadreaderapp unroll