The downside to this seemingly simple strategy is that people sometimes eat more regularly but don't scale back their portion sizes, meaning they end up taking in more food over all and ultimately sabotage their weight loss efforts. Instead of three smaller meals with three snacks spaced in between, they end up just eating 6 small meals. This perhaps alludes to the findings of a recent study concerning snacks and weight loss published in the Journal of the American Dietetic Association.
In the study, the dietary and exercise habits of over 100 overweight to obese women aged 50 to 75 were monitored for a year. One interesting result was that the women who snacked between breakfast and lunch lost less weight than those who skipped their AM snacks (7% vs 11%, respectively). Interestingly, a snack was defined as any food or beverage taken in between meals. I'm not clear on what foods or beverages the participants were choosing but drinks like coffee, tea or water with nothing added to them have no calories. And certainly there has to be a difference in outcomes between choosing a snack like an apple or some trail mix versus a chocolate bar or croissant.
In any case, the researchers don't think the results have much to do with the actual time of day that the meals and snacks were taken but rather more to do with the spacing, frequency and necessity of food intake. They suggest that mid-morning snackers might be "mindlessly" eating rather than satisfying true hunger.
Intuitively, if you throw in an extra snack in the morning and you're active, you'll work up an appetite soon after and continue eating regularly the rest of the day (that is, unless you watch every calorie and plan out your meals and snacks accordingly). On the other hand, if you wait a while and consider snacking later on in the day, perhaps closer to dinner, your day is winding down and you might be more conscious of what you've eaten throughout the day. Your decisions at that point might actually be based on true hunger.
The main message the researchers are driving home is that snacking does play an important role in weight loss, but when calories are limited, every single one counts. You've really got to get the most bang for your buck for every single calorie by choosing nutrient-dense whole foods rather than empty calories. Whole foods are naturally satisfying, particularly when they contain protein and some fats. If meals and snacks are planned appropriately and "absent-minded grabbing" is avoided, healthy eating and weight loss really can be a cinch (or at least easier!).