For most people, any holiday is a time to eat and be merry. Obviously, all that extra food has to go somewhere.
Why is that in our interest? Because knowing that would better our understanding of how to deal with it. Indirectly, this gives the obsessive amongst us a certain peace of mind (instead of running off to the gym for 3 hours the next day in a panicked state).
There are two key questions we have to ask:
- Where does all that food go?
- How Fast can you gain fat?
Where Does the Food Go?
Main point: Not all caloric excess has to be stored as fat. In fact, there are three potential ways that excess energy can be used.
- Store it
- Burn it
The first path is to funnel that caloric excess into storage.
What may surprise some people, is that storage does not automatically equal fat. In fact, many people practice structured refeeds as part of a fitness dietary regime whereby excess calories (mainly from carbs) are consumed.
I’ll talk about refeeds on another day, but what happens here is that muscles are trained in such a way that their carbohydrate stores (glycogen) are partly depleted. The excess carbohydrates then come in to “replete” these stores instead of being stored as fat.
The implication here is that training can potentially affect the way excess calories consumed after the training is stored.
That said, most people don’t train before a holiday binge (it’s time to relax), and the food is often greasy (refeeds work around carbohydrates), so we can assume that most (>90%) of the caloric excess is stored as fat.
The second pathway is that it gets burned off sub-consciously.
What I actually want to refer to is this phenomenon called Non-Exercise Active Thermogenesis (NEAT), which happens in response to over-feeding. It varies from person to person, but essentially, subconscious activity increases after over-feeding and some people literally “fidget their calories away”.
While it never accounts for the entire surplus, it is possible that say someone with high NEAT fidgets off 300kcal from a 1000kcal surplus.
Remember, this is sub-conscious activity, and can be anything from shaking your limbs to feeling the “sudden urge” to take a walk.
The caveat is that NEAT has been shown to be largely genetic; a specific person increases his/her activity to a specific level given caloric excess. There is even a study showing that some people have decreased NEAT (moving around LESS). However, for most people, NEAT generally increases, albeit very slightly in response to feeding.
The implication of that is that for most people, they “lessen” the damage of their binge through NEAT.
For some strange reason, some calories seem to disappear! I’ll explain this in a second.
So Exactly How Much Damage Can You Do? ie: What Happens in the Real World?
Theoretically, weight gain should reflect the caloric surplus. That is, if you ate 7000kcal above your maintenance caloric intake, you should have gained almost 2lbs of fat.
However, this doesn’t seem to be the case in the real world. What seems to be the case is that in short term (<24 hours) overfeeding, some of the caloric surplus seems to be lost. In other words, more often than not, if someone eats 7000kcal over maintenance, they may find out that they in fact only gained a pound of fat.
Why people often claim that it’s magic is because studies have yet to find out why this is the case. Whether it be because of behavioural changes (eating less after the binge), or inefficiencies with digestion (which seems not to be supported by the science), or any other way, we don’t know why this is the case. We just know that it happens.
So the answer is actually slightly comforting, and this is that you may do less damage than you think from that holiday binge. Of course, this doesn’t by any chance mean that you’ll not experience significant fat gain, just not as significant as you might think.
Yes, you will probably be retaining water and looking puffy due to all that sodium. Yes, you will be 3kg heavier the next morning due to the extra weight of food.