It’s 11 a.m. and I haven’t eaten in 15 hours, I’m just not hungry…but technically I should eat because breakfast is the most important meal of the day - right? It stokes metabolism - correct?
Not necessarily and nope, metabolism is calorie dependent, not frequency of feeding dependent. In English that means that your metabolism is dictated by the number of calories you consume over a 24-hour period, not the timing of those calories over the course of a day. Let’s take a look at an example…
If I eat 2,000 calories on Monday in 2 meals vs. 5 meals there isn’t a difference from a metabolic standpoint; the metabolism responds in the same way.
These days I usually consume 2 meals daily and occasionally throw in a snack if I feel like I need it. The reason behind this is that this meal cadence works great with my schedule, I feel good doing it and it’s super doable to maintain my body composition.
Some folks may call this an intermittent fasting (IF) approach where there is an ‘eating window’ in which calories are consumed and another window where ‘fasting’ occurs. As an aside, everyone ‘fasts’ for some period of time while they sleep during the night; what differs between individuals is for how long. There are pros and cons to the IF approach or blueprint so let’s take a closer look…
IF can produce fat loss benefits and the first mechanism is rather simple: less time eating equates to fewer calories consumed over the course of the day typically. Now there are exceptions to this rule because some people can easily overeat their daily caloric requirements in a very short period of time; however in general when we reduce the amount of meals and time in which we eat throughout the day, most of us consume less overall.
Also in a general sense, after roughly 18 or so hours the body shifts from using glucose (sugar) for fuel to using fats for fuel. Using fat for fuel over a period of time results in fat being burned and therefore can result in fat loss, assuming a caloric deficit (eating fewer calories than you expend) is sustained.
Another pro for IF is that when the body isn’t processing incoming food it ‘takes the garbage out’ in a sense, via a process called autophagy. Autophagy is a fancy way of saying ‘cell cleanup.’ The body accumulates by-products, harmful substances, plaques etc. so fasting for a period of time can up-regulate the processes (autophagy being one) that deal with these substances.
Intermittent fasting is a stressor of sorts…not eating for extended periods of time does cause stress on the body. Above I outlined the benefits of IF such as fat loss (which has TONS of health benefits because being overweight leads to all sorts of issues) and autophagy; however, there is a cost and benefit to EVERYTHING!
If you’re moving adequately, sleeping well and have minimal stress in your life overall, IF could potentially be beneficial for you. On the other hand, if you’re a busy Mom with a stressful job, 3 kids, drinking 4 cups of coffee daily because you’re sleeping like shit…fasting IS NOT for you; we don’t want to add an additional stress to this chaotic Mamma’s life!
Now if you’re thinking about giving the IF approach a go, be mindful that our hunger runs on of a circadian (circa meaning about, dia meaning day) rhythm so we typically get hungry at the same times every day. Being that you eat/get hungry at roughly the same times you may need to ‘push through’ some hunger when shifting to an IF approach because your body is used to food at the times in which you feed it. As a side note hunger comes in waves…you get splashed and then it subsides, you get another waft and then again it diminishes.
Who is IF for?
Folks who are interested in giving this approach a go due to the benefits, all the while mitigating the drawbacks or making sure that they don’t fall into the ‘over-stressed’ category. IF also obviously needs to fit in with your schedule; if something is incredibly difficult to implement from a lifestyle aspect, it’s going to be virtually impossible to maintain over a period of time.
Also, just because something works for a bit doesn’t mean that it’s going to work forever so be sure to keep reassessing where you’re at and whether IF (or any approach) is working or not.
Who is IF not for?
Fasting isn’t for the busy Mom above or anyone who has a similar setup. Again IF is a stressor to some degree so be extra mindful of this and recognize where you’re at with your nutrition, sleep habits, movement and stress management.
Also, IF may be something that you just want to implement once or twice a week or month - there are ENDLESS ways in which to incorporate a tactic like this so don’t think that you’re either ‘someone who fasts’ or someone who does not.
A hammer is no better than a screwdriver…IF is a tool, so it’s not superior or inferior to any other methodology, it’s all about what works for YOU at any given point in time.