OK, are dietitians wrong about dinner time? I’m about to reinterpret some 20 year old research, which really got me thinking. Though I might be mistaken, I think the experts are wrong, and the research is on my side. Such that the oft made recommendation to have or finish dinner around 6 pm is not, how is it they say it? “Evidence Based” :
Paired studies were conducted in 18 healthy volunteers (9 men, 9 women) to investigate whether differences in mood and daytime sleepiness induced by high-fat-low-carbohydrate (CHO) and low-fat-high-CHO morning meals were associated with specific hormonal responses. Plasma insulin concentrations were significantly higher after low-fat-high-CHO meals, and cholecystokinin (CCK) concentrations were significantly higher after high-fat-low-CHO meals. Subjects tended to feel more sleepy and less awake 2-3 h after the high-fat-low-CHO meal, and ratings of fatigue were significantly greater 3 h after the high-fat-low-CHO meal than after the low-fat-high-CHO meal. The results of the present study are consistent with the hypothesis that there is an association between the lassitude experienced after a meal and the release of CCK.
When I read the above research summary I get the impression that you really shouldn’t eat high fat meals if you need energy in the next couple hours. However, if you read the actual study and look at the graphs you see that both the high fat and high carb meals increased feelings of fatigue, and made the subjects feel more sleepy, with the high carb meal being just as bad or worse at various time periods of the 3 hours they looked. It’s not like they were hiding anything, it’s more that abstracts don’t always give the whole story. The paper had this fascinating quotes in the introduction:
“…subjects report feeling more feeble, dreamy, and bored and less excited, clear headed, energetic, quick-witted, friendly, sociable, and elated after lunch than they do before eating.”
…stimulation of the mucosa of the small intestine, either by a small electrical current or by the inflation of a balloon, has been demonstrated to induce sleepiness and sleep in cats”
“The pattern of afferent impulses evoked during stimulation are similar to those observed during the digestion of food, suggesting that digestive activity may contribute to the induction of drowsiness after eating.”
So that, combined with a number of other papers I have been reading about meal timing, light/dark cycles and the disruption of circadian rhythms being associated with a number of problems including daytime fatigue, poor eating habits, and depression disorders, got me thinking.
Maybe the best time to eat, and to subsequently feel tired is right before you want to go to sleep, duh. It definitely makes me think that after dinner is not the time for kids to do homework. Plus, there is the recent blog I did on a study that found people (in general) regardless of how you manipulate them are most hungry at 8 pm, and least hungry at 8 am. Yet all you hear from food experts is the importance of a good breakfast, and how you should finish your dinner early, generally 6 pm, particularly if you want to lose weight. So over the last year of my intermittent fasting I had mostly started eating at 5-6 pm, more recently 7 pm, but now I think I should start enjoying my dinner at 8 pm, live large, and sleep like a baby.
Also it’s not that I haven’t been looking for research contrary to the late dinner idea. So far I have heard that late meals make sleeping difficult (OK maybe if you have acid reflux) but I have no difficulty sleeping after Thanksgiving dinner for sure. Thus far I have not been able to locate any research that found sleep compromised after eating in regular people. I’ve heard that early dinner’s help weight loss because they increase the fasting time after dinner and before breakfast. I’ll buy that, but it sure seems a Rube Goldberg way to go about it if a late meals do in fact make people tired (WHEN THEY NEED TO SLEEP) and people are naturally least hungry in the morning (WHEN THEY NEED TO BE AWAKE). It just seems to me a whole lot easier, more satisfying, productive, best for overall physical and mental health, to increase the post meal fasting period by skipping breakfast (and lunch while you’re at it). Why? I think because it’s more in accordance with nature. That would also mean that Megan Fox, General Stanley McChrystal and Herschel Walker aren’t wrong, even if they think they sometimes think they are.
Diet experts, what are we missing?
To me it makes no sense to eat dinner at 6 pm, feel fatigued afterwards such that all I have energy for the rest of the night to do is watch TV in a horizontal position, then go to sleep around 10 or 11, just in time for my food coma (apparently well known to researchers as as postprandial somnolence) to be wearing off. So pending and likely regardless of any arguments to the contrary, I think for the next month I’m going to push my first meal of the day, dinner, to 8 pm and see what that feels like.
As always, if you have any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.
Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.