I've come to the realization that I find the 3-meals-per-day model oppressive. And I think it may be bloodtype-related.
We B's are outsiders, not settled village folk. Gathering 'round the breakfast and lunch tables may be ideal for farmers and shopkeepers, and even for some trappers and gatherers, but those of us on the move just reach down into our mounts' saddlebags - whenever - and grab a stick of jerky or a few dates or fermented milk. At day's end there's the more sociable fire, and, if the saluki dispatched a gazelle, there's a feast around the platter, otherwise a bunny, a lamb chop, or, most often, just some grain/bread and curds/whey and, later, coffee.
If you run the demographic numbers, you'll find that modern Bs are far less likely to be 9-to-5'ers than are As or Os. Bearing this in mind, you'll understand why those of us who do adapt to the standard workday struggle with what's called "meal skipping" until we (fitfully) adapt to essentially alien ways. But those of us out in the open pasture, the mountains, the deserts, aren't stopping the caravan midday to throw together what you'd call a meal.
So if you're type B and this is your (modern) situation, you might want to experiment with reconnoitering the portions into two real meals and a snack, or one real meal and two light ones. You may not be shepherding cattle down from the highlands or seeking an oasis in the Sahara, but maybe you're a freelance consultant visiting clients or an artist in a studio on your own natural timeclock with no mandated schedule. It's only my opinion and B-experience, but maybe, like this seasoned B, you've found yourself maladapting to the sit-down Breakfast, Lunch, and Dinner standard on a permanent basis.
I float the hypothesis for you bloodtype health practitioners: Scan your files for B cases with meal-skipping tendencies. And bear this in mind: A number of ABO personality theorists remark that many B's are driven to focus on a project/task ( I call it "burrowing") for very long uninterrupted stretches, hours on end. Rather than simply notice it and smile about it, maybe we should be respecting it, not expecting Bs to break for a workout, as an O might, or a nap or yogic pose, as would an A, let alone for a meal.
I posit that Bs mealskip because of deeply rooted anthropologic-genetic factors, and that diets, and especially portions, should take this gene-linked tendency, this ingrained adaptation of a small percent of our population, into account. From my B point of view, we're not skipping anything. Though devotees of the currently dominant cultus chastise us ("You call that breakfast?!" or "Don't you want to stop for lunch now?"), it's only because they haven't eyes for the vast steppe we're traversing.