Beyond Macros - let’s embrace our nutritional complexity

We are in an era of strong scientific enquiry and integrity, where we look to scientists to help us explain the mysteries of our human body, and where we look for ‘the’ answer to certain health and performance conundrums.

Within our field of sports nutrition, no subject has been studied more than that of macronutrient consumption. The 2016 American College of Medicine joint position statement sums up our current thinking nicely, with a strong focus on carbohydrate, fat and protein consumption, and only a brief mention of a select few micronutrients that have reached a certain research threshold within sports performance (1).

To understand the context of modern scientific enquiry, it actually helps to look at the history of sports nutrition research. I did this with a 2017 article in the FSN magazine (2), in which I noted that sports nutrition research evolved out of exercise physiologists’ laboratories. It was relatively easy for them in the 1960s and 70s to measure muscle glycogen levels (via biopsy) in exercising individuals. In my mind, by the time the 1980s had finished, there had been adequate research to demonstrate the importance of carbohydrate availability for athletic performance. Notable names from that era included David Costill, Per-Olof Åstrand, Edward Coyle and Andrew Coggan, all of whom clearly demonstrated that endurance performance was better when muscle glycogen levels were replete versus depleted (e.g. 3,4). Our current understanding of exercise biochemistry also backs up these early observations, knowing that the Krebs cycle utilisation of carbohydrate provides a higher ATP flux rate than that of fat or protein.

Even now, some 50+ years of sports nutrition research later, scientific enquiry still centres around carbohydrates – I think researchers sometimes cling too tightly to their ‘carb paradigm’ at a time when we really should be widening our net and thinking in a more diverse way.

In this regard, the last decade of research has been interesting due to a phenomenon that I might call the ‘keto re-revolution’. It is a phase that I thought we’d passed through and learned from during the Atkins diet era, but in recent years, scientists have been publicly disowning the carbohydrate paradigm and trading in their bread for bacon plus an extra portion of butter… At no other time has opinion been so divided on the carbs versus fats debate. As a popular example, within a year of one another (2015-16), two highly eminent scientists published best seller books that had pretty much opposite messages: Prof Tim Noakes from the University of Cape Town published The Real Meal Revolution, popularising the concept that ‘fat is good’ and ‘carbs are bad’, while Colin Campbell re-published his China Study book, showing apparently unequivocal data that correlated animal-derived protein consumption with cancer rates. Although Campbell was talking about protein and not fat, if you have ever tried a keto approach, it is incredibly difficult to keep your animal-derived protein levels at a sensible level.

This is just one example of extremely divergent paradigms at a time when we should be seeing things in a deeper and more complex way, just as our human physiology and biochemistry dictate. The science of nutrigenomics is hitting its 20-year anniversary. Some researchers within sports nutrition still stand strongly behind their chosen paradigm, saying that there is not enough data within this field for us to take genetic individually seriously – but I see that action akin to an old school doctor standing firmly behind his or her script pad, saying that there is no data to support nutritional or herbal medicine. Seek and ye shall find….

With genetic individuality in mind, I only follow the findings of a genetics test if it makes cognitive and intuitive sense to me as a practitioner. And that ‘sense’ has been honed by many years of observing people, not to mention a 90-minute initial case history with the individual in question. As a practitioner working 1-on-1 with people, it is incredibly obvious that some individuals thrive more on a higher fat diet, while others need a consistent intake of high-quality carb sources to perform at their best. It’s also clear that some people can go for hours without seemingly needing food, and they therefore fare much better with intermittent fasting regimes, compared to others who simply stress their adrenal reserve by fasting. Scientists can only conduct their research by studying several subjects simultaneously – enough people to gain statistical significance if their initial hypothesis has any merit. In this way, scientists cannot help but to create one-size-fits-all observations. The concept of n=1 (i.e. each subject is unique) is slowly coming into science, but it will be a while before subjects will be studied individually. In contrast, that is what observant practitioners do on a daily basis, meaning that they can look beyond macronutrient paradigms, and actually tailor a nutritional approach that provides that individual with long-term nourishment.

Besides debating about the individual merits of carbs, fats and proteins, we should delve a bit deeper and go truly ‘beyond macros’. If we return to the Krebs cycle and the electron transport chain (which produces ATP), and look at the micros that are required as catalysts for the biochemical conversions, we reveal a strong need for B-vitamins, zinc, iron, magnesium, coenzyme Q10, manganese, and alpha lipoic acid (5). And this is only for direct ATP production – athletes also need every physiological process in the body to work well, including neurotransmitter production, liver biotransformation, collagen repair, and immune cell manufacturing, which brings every known micronutrient into importance, not just those that have been studied within a performance perspective. Additionally, if we don’t protect the delicate mitochondria that produce our energy, despite sufficient macronutrient provision, we will end up with multiple physiological dysfunction. Notably, mitochondrial pathology has been linked with chronic fatigue syndrome, fibromyalgia, and a cacophony of other health imbalances (6), none of which would be suitable for peak athletic performance! Antioxidants from food, and our innate antioxidant systems (glutathione, superoxide dismutase and catalase), are required in large quantities to buffer the systemic oxidative stress that results from heavy exercise training, most notably at the level of the mitochondria.

To finish, let’s continue the mitochondria story a little further. Another research enquiry of the last decade has been around the transcription factors for mitochondrial biogenesis, in particular AMPK and PGC-1α. Team Sky nutritionist James Morton, and colleagues, have demonstrated that training in a glycogen-depleted state bolsters AMPK activity (7), which obviously is a positive observation when it comes to mitochondrial activity. However, they also observed that glycogen depletion resulted in a compromised time to exhaustion in cyclists, plus a reduction in p70S6K activity (protein synthesis and cellular growth), which might inhibit recovery. In other words, there are pros and cons to training in a glycogen-replete or -depleted state, and an athlete must be very educated on this topic to avoid a possible regression in performance when they manipulate glycogen levels.

However, if we look at other possible upregulators of AMPK and PGC-1α, we enter the domain of micro- and phyto-nutrition: l-arginine, lipoic acid, biotin, resveratrol, quercetin, pterostilbene, which are also some of the antioxidant protectors of mitochondria, have been shown to upregulate PGC-1α activity (8,9).

In conclusion, we can argue as much as we want about the type and quantity of fuel (macronutrients) to put in our human high-performance engine, but if we haven’t nourished our spark plugs with micro-nutrition and looked after every other part of our body and chassis, we’ll literally be running on empty, no matter how many fats or carbs we consume.


  1. American College of Sports Medicine, Academy of Nutrition and Dietetics & Dieticians of Canada (2016). Nutrition and athletic performance - Joint Position Statement. Med Sci Sports Exerc. 48(3):543-568.
  2. Craig I (2017). History of sports nutrition - a 50-year review. Functional Sports Nutrition. July/August 2017.
  3. Coyle E et al (1986). Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. J Appl Physiol. 61:165-172.
  4. Coggan A & Coyle E (1989). Metabolism and performance following carbohydrate ingestion late in exercise. Med Sci Sports Exer. 21:59
  5. Lord & Bralley (2008). Laboratory Evaluations for Integrative and Functional Medicine. Metametrix Institute. Second Edition.
  6. Teitelbaum et al (2006). The use of D-ribose in chronic fatigue syndrome and fibromyalgia: a pilot study. J Altern Complement Med. 12(9):857-862.
  7. Impey SG et al (2016). Fuel for the work required: a practical approach to amalgamating train-low paradigms for endurance athletes. Physiol Rep. 4(10):e12803.
  8. Ventura-Clapier et al (2008). Transcriptional control of mitochondrial biogenesis: the central role of PGC-1a. Cardiovascular Research. 79:208–217.
  9. Evans (2009). The secret life of mitochondria.