Here it is:
And my thoughts for your ruminating pleasure:
Not very accurate, but fits with the general populace’s understanding of these mechanisms. The reality is that there are many metabolic mechanisms at play in the use of macro and micronutrients that aren’t easily quantified by simple statements.
Square 1 – incorrect. While the brain is the major consumer of blood glucose, there is plenty stored in and used by the muscles themselves. You need a dotted-arrow pointing at the body. Also, not all food “not-used” is stored as fat. Depending upon the metabolic profile of the individual, much unused food can simply pass through the digestive system.
Square 2 – I’m not sure that the mechanism is that simple. In addition, what is used and when definitely varies depending upon what the demand is (e.g., intense physical exertion or couchsurfing).
Square 3 – again, too simplistic. If there is a high-intensity demand, the body will use only body-based nutrients. Hence the admonition against doing vigorous exercise immediately after eating – the body will neglect the ingested food in favor of immediate (body-based) reserves.
Square 4 – too simplistic still. What is burned when the body is in a fasting state depends upon the horomonal/metabolic profile of the individual, and the activity (type/quantity/intensity) prior to the fasting state.
Square 5 – Better to look at the next few squares in terms of the general concept of SUBSTRATES. The body will (attempt to) use what it has at-hand. If there is a demand for protein (e.g., to rebuild) and there is none available, the rebuilding process will be stunted.
Square 6 – Very difficult square. What type of weight training, at what intensity? What about bodyweight training? (plenty of shredded gymnasts out there). What about “cardio?” (there are plenty of shredded, though not “muscular,” long-distance runners). In addition, what is a “fat-loss diet?” It is very possible (and preferable) to lose body-fat while building muscle. The “fed-state” is an important concept that is misapplied. It goes back to the SUBSTRATES concept.
Square 7 – This is very arguable. Low intensity cardio may burn a higher percentage of fat compared with protein, but it does so at such a low level (overall) that it may not be worth mentioning. Instead, focus on low-intensity cardio as a means for speeding recovery between intense exercise sessions – spreading the nutrients and pumping the system.
Square 8 – Completely wrong. Do high-intensity activity on an empty stomach and as long as you refuel properly within your window (usually anywhere between 20min-2hrs) your body will recover fine and burn just as many nutrients as it would otherwise. I see more “skinny-fat” people coming from the Yoga community than from anywhere else. And they aren’t performing any high-intensity exercise. High intensity on a full stomach = vomiting.
Finale – Consider energy/macronutrient use from the perspective of the demand-systems. The aerobic system works constantly (you’re using it now). The anaerobic system turns on to meet high-intensity demands of various levels. Each system is also connected to a different branch of the CNS, with different hormonal profiles, and different “preferred” energy sources.
I challenge these guys to make a better infographic!!!