Of all the existential questions humans have faced throughouthistory, some questions are more existentialer than others. What is the purpose of life? Is there a god? What is the origin of life? Can we derive values from facts? Is there an afterlife? Does the Snyder Cut exist? All of these are questions that have preoccupied the neuronal space of great and formidable minds. From Plato, Aristotle, and Hume to Richard Dawkins, Sam Harris, and Jordan Peterson; philosophical giants have wrestled with and sparred over these deep and fundamental queries that touch upon the most elemental foundations of the human condition and question the very fabric of reality. However, one must then ask, did/do they even lift? Bro? For as deep and ever-pressing a question as “where do we come from” or “are we alone in the universe”, perhaps no question has plagued and tortured, mentally and physically, and elicited more confusion in the minds of earnest truth-seeking, selfie-centered humans than “should I cut carbs?”
Indeed, this question has inflicted pain, misery, suffering, and richter scale-registering confusion on masses of weight loss-, hypertrophy-, and spring break-minded individuals. No other macronutrient in history has tortured and taunted the lean-seeking, cut-obsessed, and recently single like the (CH2O)n. The sight of a slice a bread to the carb-cutting can bring a grown adult to tears; a strawberry short cake, PTSD. Meanwhile, to the carb-loading, every meal is the 4th of July Coney Island Hot Dog Eating Contest, where they channel their inner Kobyashi and replace the hot dog with another bun filled with another bun filled with pasta, in a bowl of Quaker Oats, and wash it down with waxy maize until every single muscle fiber atop their skeleton lies on the brink of rupture from glycogen supercompensation. So much glycogen. So much, I can’t even. Every workout becomes something like tactical airstrike with minute-by-minute carb replenishing strategies to replace every oxidized glucose molecule and stave off the ever-menacing glycogen depletion. This ultimately manifests into carrying around over-priced Hawaiian Punch you bought at a supplement shop in an old water gallon jug, sipping between each rep or stride, and downing 117 bananas or three liters of chocolate milk post-workout. Somehow a Zumba class has been confused for the Tour De France.
Now, one can be forgiven for embracing such extreme and, at times, ridiculous nutritional practices; there is bad and conflicting information everywhere.
“They” say carb up and carb down. Which one is it?
Carbohydrate intake within the context of fitness and health, particularly, with respect to body composition (fat loss, muscle mass gain) and for exercise (fueling, recovery) is a snake pit of a topic, with no apparent consensus on whether or not carbs are “good” or “bad”. Moreover, in the realm of fitness and exercise nutrition, the topic seems to have become an ideological one, where one is fervently “pro-low carb and anti-high carb” or “pro-high carb and anti-low carb” and demonizes the opposing diet. Additionally, in this debate, anecdotal evidence reigns supreme; especially on social media. Claims of incredible and rapid fat loss, newfound, endless energy, insane muscle gains, and, finally getting the six pack you’ve always wanted can be seen on Instagram, YouTube, and magazine covers for both low carb and high carb diets. Ask any gym-goer or trainer about carbs and you’ll get a wide range of random shit to eat, not eat, do, don’t do such as: eat a carb every meal, don’t ever eat carbs, don’t eat carbs after 8 pm, don’t eat potatoes, eat carbs immediately before your workout, eat carbs immediately after your workout, eat carbs during your workout, don’t eat bananas, don’t eat leafy vegetables, don’t eat onions, only eat whole grains, don’t eat carrots, eat simple carbs only after your workout, don’t eat babies; the list is virtually endless and increasingly enraging.
Traditional sports/training nutrition guidelines recommend a fairly high daily carbohydrate intake of around 60 – 70% to fuel training and make gains . At the same time, low carb diets, ranging from 10 – 40% of caloric intake, have gained notoriety and found their way into the sport and exercise nutrition realm. Paleo, keto, the Zone diet, to name a few, are diets have been touted as efficacious means to promote fat loss, increase muscle mass, and even enhance exercise performance and training outcomes (i.e. get shredded/cut/hella jacked). Which of these propositions are true?
Well, there is a technical problem arising here. When looking at dietary recommendations, one must ask, do these recommendations technically pertain to me?
Fueling exercise: how much and how to refill
When reading the literature on training and nutrition, one will find that many of the guidelines pertain to athletes, or at least seriously training individuals. These guidelines typically don’t pertain to the average, mere-mortal gym-goer; they are aimed for sport and sport training performance. Moreover, many of these recommendations have to do with endurance-based exercise (i.e. long-distance, long-duration exercise). Very little literature exists examining carbohydrate needs for, say, resistance training (I have published a review on this very topic), CrossFit, or interval training and none exist for recreational fitness programs like boot camp fitness, spin classes, or Bar Method.
If one looks at some main carbohydrate guidelines, one will find that they are a bit more nuanced then “eat a lot of carbs” or “eat zero carbs”. The Academy of Nutrition and Dietetics, Dietitians of Canada, and American College of Sports Medicine (ACSM) recommend 3 – 5 grams/kg of body weight per day for low-intensity or skill-based activities and 8 – 12 g/kg for very high training demands . The International Society of Sports Nutrition (ISSN) recommends a daily intake of 5 – 10 g/kg for moderate to high volumes of intense training (“upwards to 12 hours per week) .
While everyone that enters a gym with a “Beast Mode on”, “Go Big or Go Home”, or “I Don’t Sweat, I Sparkle” tank or tee shirt and Dre Beats thinks their spin class or box jumps were essentially Olympic-level training, most gym-goers (non-competitive athletes), objectively, just don’t train that hard; despite all the locker room selifes and #fitlife’s. Most mere mortals simply are incapable of bearing that intense of a training load, nor do they have the time to. This is not to imply one is not “working hard”. Subjectively, anyone can exercise hard; to fatigue, to exhaustion. But from an absolute standpoint, the fitness enthusiast and beach body-minded cannot train at the same level of someone who’s livelihood depends on physical performance or appearance; populations where these high carbohydrate intakes are warranted. Sadly, a positive linear relationship between training intensity and hashtags does not exist.
This is not say, however, that a high carbohydrate diet for exercising individuals is detrimental. It is not detrimental in the least. However, in most cases, for most people, it is not necessary.
But you can.
In most cases, for most people, a normal, unspecial, unsexy, non-Instagram attention-grabbing diet is sufficient. #sorryimnotsorry
If I lift all the weights, do I eat all the carbs?
In the complex world of bros, barbells, and beta-shaming, carbs have been seen as both the messiah macronutrient, the key to amassing mass on a massive scale, as well as the Thanos of the food pyramid, destroying half of your lean muscle mass and disintegrating half of your abdominals with a single snap of the fingers (or a single bite of a Krispy Kreme doughnut). Carbohydrates have been proposed to be, at the same time, absolutely necessary and absolutely deadly for resistance training individuals trying to get their Henry Cavill-mega-ultra-alpha physique on. It has been thought that carbs are needed to build muscle for namely two reasons; 1. Carbs are needed to fuel resistance training and, 2. Carbs elicit an insulin spike, and insulin is anabolic. Bro.
Firstly, carbs are, indeed, used for fueling resistance training, but actually how much of that fuel is being used? A typical bodybuilding/strength training workout uses approximately 25 – 40% of a muscle’s glycogen stores [4-6] (think, the pecs use that much glycogen on chest day); there’s between 75 – 60% of the fuel left in that tank. Which is not zero, bro. And there are likely at least a two to three days between training that muscle group again. That is more sufficient time to replenish glycogen; even if you don’t consume any carbohydrate. Glycogen is restored at a fairly quick rate even when no carbs or food are consumed. A study measured glycogen after #legday immediately post-exercise and then 2 hours post-exercise where during the 2-hour period subjects were not fed. Immediately-post, glycogen levels were 61% of pre-exercise levels, two hours later they were 79% of pre-exercise levels; an 18% restoration when no carbs or food were consumed . Odds are the risk of glycogen depletion during resistance training is extremely low. Aragon and Schoenfeld, in their debunking of the “anabolic window”, state, “incomplete resynthesis of pre-training glycogen levels would not be a concern aside from the far-fetched scenario where exhaustive training bouts of the same muscles occur after recovery intervals shorter than 24 hours” . Bodybuilding bros who train exclusively for right swipes, are not going to run out of glycogen if they don’t chug the overpriced Hawaiian Punch or eat eight rice cakes as soon as they put the dumbbell down.
The other claim for carbohydrate need, particularly post-exercise, is that carbs elicit an insulin response and that insulin is an anabolic hormone. This is technically true; however, one would have to eat a whole cereal aisle of carbohydrate to elicit a strong enough insulin response to stimulate muscle protein synthesis. Chocolate milk, a couple bananas, or a Snickers bar are not going promote muscle anabolism. Insulin is not an anabolic hormone; within a muscle protein synthesis (i.e. hypertrophy) context . There is no difference in muscle anabolism between carb and protein ingestion vs. protein alone . In fact, when protein is consumed, the anabolic machinery is turned on and the insulin signaling pathway is actually inhibited [11, 12]. So, slamming poorly-imitated cinnamon roll flavored hydro-mega ultra isolate whey with a Tupperware of white rice or warm, bruised bananas yield no additional anabolic benefit to slamming the poorly-imitated cinnamon roll flavored hydro-mega ultra isolate whey by itself.
But you can.
Consuming 20 – 40 grams of complete protein (a shake or real food) within 4 hours of exercise (before or after) is sufficient enough to get anabolic. So anabolic.
Carbs and body fat: cut them to cut it?
Much has been made about low or no carb diets and the need to cut carbs in order to lose body fat. So far as we can tell, this is false. Though it has become a popular idea and commonly practiced type of diet, the data do not show that low/no carb diets are superior than the recommended traditional “western” diet of moderate to moderately-high carb intake of 45 – 65%  in promoting fat loss. While some studies have shown low/no carb diets to produce fat loss, there have not been any studies that have compared a low/no carb diet to a traditional higher carb diet while matching for calories and for protein intake (as in both diets contained the same amounts of calories and protein so a direct comparison can be made). Claims that low/no carb diets are better than higher carb diets for fat loss are simply unsupported; except perhaps on fit bro, yoga panted Instagram pages, but PhD’s in being attractive don’t quite hinge on scientific literacy.
If the claim that carbohydrate intake was more important than calorie intake for body fat were indeed true, whoever made such discovery would win the Nobel Prize. In physics. For defying the law of thermodynamics.
In the ISSN’s position stand on diets on body composition, where all the relevant literature had been reviewed, they concluded that similar results in fat loss can be achieved using low carb diets, low fat diets, or anything in between and that the carbohydrate-insulin hypothesis of obesity is simply not valid .
The key to promoting fat loss is reducing calories (and, sure, exercise may help some). This can be explained evolutionarily. We did not evolve in the current circumstances that we find ourselves now, where food is abundant. We evolved under food insecurity and the amazing access to food we currently have, coupled with our evolutionary-derived instinct to eat whenever food is available, has led to a species-level issue of obesity (although we should view obesity as a condition of fortune and a testament to human achievement from a species perspective). Humans are simply not wired to eat as much as we do now or would certainly like to.
Reducing calories is the key thing in losing body fat. That may come from cutting from any food group; carbs, fat, or protein (although maintaining or even increasing protein intake during calorie cutting will help maintain lean body mass). It is calories that are stored as fat tissue. It’s not the carb, fat, or protein, per say, but the calories contained within them that produce fat. If one consumes an excess of 400 calories, it does not matter what nutrient those excess calories come from. Further, it does not even matter what food those calories come from; whether it’s grilled chicken breast, brown rice, avocados, a bowl of organic non-GMO kale that costs $17 a pound, or chocolate cake, pizza, ColdStone Ice Cream, a stick of butter, or an In-n-Out 4×4. Your cells cannot tell where the calories are coming from, they are just energy that are used or stored. The only thing that matters is controlling calorie intake. And while a daily diet of chocolate cake and sticks of butter may not be ideal for overall health, from a fat loss/fat gain standpoint, they are just calories.
While there is a case to be made that proteins and fats may keep you fuller longer than carbohydrates and that higher-protein diets, in particular, are good for fat loss, this simply comes down to which “diet” leads to less calories at the end of the day. This gives one absolute freedom in choosing foods and creating a diet that one wants and can actually manage. So, if you want to lose body fat, you do not have live under the tyranny of a rigid diet, cutting carbs and never eat anything delicious like donuts and bacon again.
But you can.
Calories are calories. Count them but enjoy them.
The convenient (and delicious) of all existential questions
Unlike the other deep, universal questions that have plagued humanity, the answer to the question of “should I cut carbs?” is one of personal choice; which is rather convenient. One could imagine if the answer to “are we alone in the universe” was up to personal choice, one could answer “yes, and Cybertron is real and my car is a deadly robot. Roll out”. High carbohydrate diets are not needed to fuel most exercise or to promote muscle mass gains. Low/no carb diets are not superior for losing body fat. Those are the latest data and are the best foundation one can use to inform themselves. To improve body composition or optimize training, one can choose foods they want and like rather than creating a “diet” per se. This can be incredibly helpful in long-term success and help achieve the body composition goals one aspires to.
- Costill, D.L. and M. Hargreaves, Carbohydrate nutrition and fatigue. Sports Med, 1992. 13(2): p. 86-92.
- Thomas, D.T., K.A. Erdman, and L.M. Burke, Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet, 2016. 116(3): p. 501-528.
- Kerksick, C.M., et al., International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr, 2017. 14: p. 33.
- Robergs, R.A., et al., Muscle glycogenolysis during differing intensities of weight-resistance exercise. J Appl Physiol (1985), 1991. 70(4): p. 1700-6.
- Camera, D.M., et al., Early time course of Akt phosphorylation after endurance and resistance exercise. Med Sci Sports Exerc, 2010. 42(10): p. 1843-52.
- Roy, B.D. and M.A. Tarnopolsky, Influence of differing macronutrient intakes on muscle glycogen resynthesis after resistance exercise. J Appl Physiol (1985), 1998. 84(3): p. 890-6.
- Pascoe, D.D. and L.B. Gladden, Muscle glycogen resynthesis after short term, high intensity exercise and resistance exercise. Sports Med, 1996. 21(2): p. 98-118.
- Aragon, A.A. and B.J. Schoenfeld, Nutrient timing revisited: is there a post-exercise anabolic window? J Int Soc Sports Nutr, 2013. 10(1): p. 5.
- Abdulla, H., et al., Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis. Diabetologia, 2016. 59(1): p. 44-55.
- Staples, A.W., et al., Carbohydrate does not augment exercise-induced protein accretion versus protein alone. Med Sci Sports Exerc, 2011. 43(7): p. 1154-61.
- Tremblay, F. and A. Marette, Amino acid and insulin signaling via the mTOR/p70 S6 kinase pathway. A negative feedback mechanism leading to insulin resistance in skeletal muscle cells. J Biol Chem, 2001. 276(41): p. 38052-60.
- Patti, M.E., et al., Bidirectional modulation of insulin action by amino acids. J Clin Invest, 1998. 101(7): p. 1519-29.
- USDA, U., 2015 – 2020 Dietary Guidelines for Americans, 8th Edition: U.S. Government Printing Office. 2015.
- Aragon, A.A., et al., International society of sports nutrition position stand: diets and body composition. J Int Soc Sports Nutr, 2017. 14: p. 16.