The Daily Mail has a story(1) about research(2) showing that a high-fat diet makes you sleepy. (See abstract 0977 in the research link.) This flies in the face of my experience and a whole lot of anecdotal experience, too (see the comments to the article). Since starting a low-carb, high fat diet, I haven't needed four-hour naps on the weekend. (See this, this, this, and this.) I'm not exhausted come 7 p.m. on a Friday night. I have the energy at 44 that I should have had in my twenties. Are we low-carbers violating some law of physics or biology? No--the research and Mail article are magic tricks.
The article is called "Why the Atkins Diet will make you sleepy but a packet of crisps will wake you up." Atkins is a specific diet: 20 grams of carbohydrate per day during induction with adequate protein and fat; most of Dr. Atkins' patients couldn't go over 40 grams of carbohydrate per day without gaining weight. Yet the research article that it refers to doesn't mention the Atkins diet. It also doesn't mention what the participants were fed or how much carbohydrate their meals contained.
One magic trick that low-carb scare studies use is calling a medium-carb diet a low-carb diet. The journal article calls the meals "high fat"; it doesn't say whether the meals were also high-carb or high protein or something in between.
Another magic trick is studying a low-carb diet for less than two weeks, about the amount of time it takes to adapt to such a diet. The study in the journal was conducted over four days. It's not unusual to be a little tired for the first couple of weeks on a low-carb diet.
1. "Why the Atkins Diet will make you sleepy but a packet of crisps will wake you up" by Emma Innes. Daily Mail, May 8, 2013.
2. "High Fat Intake is Associated with Physiological Sleepiness in Healthy Non-Obese Adults" by Kritikou I, Pejovic S, Vgontzas AN, Fernandez-Mendoza J, Bata M, and Bixler EO. Journal of Sleep and Sleep Disorders Research, Volume 36, 2013, Abstract Supplement, article 0977.
The article is called "Why the Atkins Diet will make you sleepy but a packet of crisps will wake you up." Atkins is a specific diet: 20 grams of carbohydrate per day during induction with adequate protein and fat; most of Dr. Atkins' patients couldn't go over 40 grams of carbohydrate per day without gaining weight. Yet the research article that it refers to doesn't mention the Atkins diet. It also doesn't mention what the participants were fed or how much carbohydrate their meals contained.
One magic trick that low-carb scare studies use is calling a medium-carb diet a low-carb diet. The journal article calls the meals "high fat"; it doesn't say whether the meals were also high-carb or high protein or something in between.
Another magic trick is studying a low-carb diet for less than two weeks, about the amount of time it takes to adapt to such a diet. The study in the journal was conducted over four days. It's not unusual to be a little tired for the first couple of weeks on a low-carb diet.
1. "Why the Atkins Diet will make you sleepy but a packet of crisps will wake you up" by Emma Innes. Daily Mail, May 8, 2013.
2. "High Fat Intake is Associated with Physiological Sleepiness in Healthy Non-Obese Adults" by Kritikou I, Pejovic S, Vgontzas AN, Fernandez-Mendoza J, Bata M, and Bixler EO. Journal of Sleep and Sleep Disorders Research, Volume 36, 2013, Abstract Supplement, article 0977.
Comments
But, hold on a sec, don't crisps also contain a lot of fat?
If you're on a 2k cal per day diet, and your macronutrient ratio is 10% carb, 35% protein & 55% fat, that's around 50g carb & 122g fat. From that point of view, it's a high-carb snack.
If you're on a low-fat diet (10% fat on 2k cal per day), you're allowed 22g of fat. At 55% carb, you'd be allowed 275g of carb. The fat would blow your diet for the day.
Personally, I think of potato chips as a high-carb food, but it's relative to what your plan is.
Lots more still needs to be done to cast out the LCHF myths, and re-enforce the good news.
All the best Jan.
If in the past our ancestors had run out of food, then their brains would be running on ketones (which provide more ATP to the brain per unit of oxygen used according to my monster book of metabolism). It is the ones whose brains worked well on ketones and could function well enough to hunt that would have survived.
It makes no evolutionary sense at all that a keto (ie high fat) diet makes you sleepy! Anyone who had that problem would have died out eons ago.
A high carb, high fat diet however is another thing entirely. Researchers don't usually know the difference between a high fat diet and a keto diet.
Carole AKA CarbsaneR