I thought that we would have evolved with irregular meal-times, and the evidence would demonstrate the desire for regular meal-times was an "old wive's tale". I was surprised by the evidence, which does support the idea of regular meal-times.
Energy after Eating
Nine lean women were given regular meals and irregular diet with up to 9 meals per day.
CONCLUSION: Irregular meal frequency led to a lower postprandial energy expenditure compared with the regular meal frequency, while the mean energy intake was not significantly different between the two. The reduced TEF with the irregular meal frequency may lead to weight gain in the long term.
(Note: The last sentence is speculation. They did not observe weight-gain during the trial.)
The same authors tried it again with obese women:
Ten obese women were put on regular and irregular meal times for two weeks:
Conclusion: Regular eating has beneficial effects on fasting lipid and postprandial insulin profiles and thermogenesis.
Some other studies show some less directly related, but still interesting, results:
In Your Head
- This study shows that "dinner time" hunger may be more about what time your head thinks it is, rather than the state of your stomach.
Regular Family Meals
Related to the idea of regular meals, is the idea of regular family meals. There are a number of positive social effects related to regular family meals.
In Finnish children, not having a regular family dinner is correlated to eating more sweets, more problematic behaviour and a lower socio-economic class. I would tentatively suggest the causation is more likely to flow from the socio-economic class towards the other items.
In Minnesotan children, regular family meal times was associated with healthier eating five years later. Again, I suspect socio-economic class and education to be a confounding factor. (Same authors)
Meal Frequency - Nibbling versus Gorging
Just because you have regular meal times, doesn't mean there aren't a lot of them throughout the day.