Discussions of the art of writing fanfic: musings, examples, meta. and advice.
Superhero Metabolisms and the Fic Writer
Those of us who write superhero fanfic often mention offhand that, say, an Avengers dinner could feed a small army. Here are some references on the topic, with a bit of commentary.
Superheroes with powers derived from magic or the like aren’t as much of a concern, because magic. However, when you are dealing with science-derived powers (super soldier serum, for example) or powers that are biologically inherent to the person (mutants, possibly Inhumans), that has to get powered somehow. Unless they’re able to photosynthesize or something, that somehow is through food. Then there are the superheroes who aren’t physically powered, your Hawkeyes and Batmen. These are standard-issue humans in top physical form.
So, what does it take to fuel an Avenger? The best references are to look at real-world examples, the nutritional needs of actual elite athletes, soldiers, body-builders, and the like. A few examples I’ve been able to track down are below. Note: If you have any useful stuff to add, please do!
Person: Dwayne “The Rock” Johnson Purpose: Playing Hercules in a movie Diet: 5,165 calories a day, in 7 meals. “Highlights” include 36 oz of cod and a 10-egg-white omelet. Training: Intense training 6 days a week
People: US Active Duty Military
Purpose: Being on active duty in the military
Diet: Ranges depending on where they are stationed and what they do. Vigorous training or physical activity, high or low temperatures, and high altitudes also increase caloric needs. The US Army nutrition standards provide a really useful snapshot:
For reference, these standards say that the MDRIs should be altered as follows:
- Size: These were calculated for a 174-pound man, 5′9″ man or a 136-pound, 5′4″ woman. Needs will be higher for bigger people and lower for smaller people.
- Cold: Moderately chilly temperatures (above freezing but below 57F) will increase energy needs by 5-10%. Extreme cold, and especially heavy work in extreme cold, will increase these needs even more. If your characters are snowshoeing through the arctic, they might need to eat more than 60 calories per kg of body weight.
- Altitude: Energy requirements go way up when you get up above 10,000 feet. If you’re up that high and working hard, you may burn 6,000 to 7,000 calories a day.
So, what does all this mean for superheroes?
Caveat: Not a dietician or exercise physiologist, but here are some extrapolations based on the above information and what we know about various comic characters from canon. Take all of this with a pinch of COMICS SCIENCE! salt.
Super soldiers like Steve Rogers are supposed to be the pinnacle of human possibility. Basically, the serum enhanced Steve so that every bit of him was as good as a human could ever possibly get, physically speaking. I imagine he probably has the friendliest possible metabolism, one that adapts to his circumstances pretty well, so that he can maintain that physique just as well with cheesecake as with cod and doesn’t have to put in the levels of training that the others do. However, the energy to do all that healing and run that body have to come from somewhere. Assuming that the serum enables his metabolism to speed up and slow down according to his energy needs, I would imagine that Steve would need to eat something like 3500 calories a day on a “normal” day but that if he trained hard or fought it would shoot up into the 5-6K range. On days when he is recovering from exertion or, especially, healing, it might not be unreasonable for his body to burn through 8-10K a day.
People who have various lesser versions of the serum - comics Natasha and Nick Fury, Bruce, Bucky, etc - would likely fall somewhere between Steve’s requirements and those of an unenhanced person.
People with biologically-based powers like mutants or Inhumans probably have nutritional needs based on how often and intensely they use the power. Daisy Johnson from Agents of SHIELD has the normal needs for an unenhanced person of her size and activity level, but using the power probably counts similarly to vigorous exercise. Once or twice, it’s probably like a workout; if she’s fighting for an extended time or doing big things like collapsing a hanger, her energy needs might nearly double. People with powers that are always “on” might have a metabolism more like Steve’s.
Unenhanced heroeslike Batman or Hawkeye probably fall somewhere in between the US Army chart and The Rock’s regime. To keep in shape, these people have to work very hard. Olympic gymnasts train 30+ hours a week, and that’s probably about right for your standard-human superheroes. Their training will be intense and targeted and will include cardio/endurance training (for chasing baddies), weight training (for lifting their own body weight when they climb buildings, for carrying rescued people, for lifting rubble, etc), and flexibility/gymnastics/dance training (for all those sweet bullet-time dodges and acrobatics) as well as fighting technique, martial arts, and weapons training. SHIELD probably employs a large stable of trainers, dietitians, and sports medicine experts to keep their field agents in top shape, and I imagine the independent Avengers do too. Both organizations likely also provide amenities like hot and ice tubs, massage, etc - the sorts of things provided to professional sports teams. They probably also have pretty strict meal plans - lots of cod.
What does this mean for my story?
It opens up some fascinating avenues to explore!! Here are just a few:
- If you are writing Bucky on the run, how does he feed himself? Is he getting what he needs? Does his metabolism slow to try to preserve his health?
- If you are writing a cold-weather survival story, food becomes a MASSIVE issue! Even if they don’t freeze, they could starve much faster than normal. Not having sufficient calories could make them weaker and make it harder for them to think, plan, and make good decisions.
- If you are writing SHIELD agents who are undercover as people who don’t spend many hours a week at the gym, how do they deal with that? Their bodies would be accustomed to eating and expending much more than normal. They would likely feel restless and hungry all the time and really struggle to adjust. They might find opportunities to sneak in extra workouts or the like.
- They might very well need to carry quick-energy solutions like glucose gels, as well as supplements like protein bars, with them at all times and definitely while they’re training or fighting, similarly to how endurance athletes do. Those utility belts probably have at least one compartment dedicated to snacks. I could see, in short breaks in the fighting, Avengers or agents being reminded to top up their energy, especially those who have powers. This could also be a source of danger/tension in the plot: the Gifts series is a great example of this, creating a world where powered people can actually put themselves into severe hypoglycemia, potentially even killing themselves if they try to do too much too fast (like, say, someone with a shield ability trying to shield someone from a missile strike.)
- If you are writing slice-of-life or outsider POV, think about HOW MUCH shawarma the Avengers probably ate after the BONY, how giant a snack Alfred probably needs to have ready for Bruce Wayne, the sheer size and scope of the Avengers Tower standing grocery order. How much that all COSTS, and what that means to those heroes like Daredevil who don’t have a billionaire or a spy agency paying their grocery bills.




Thanks! This was very timely.
Thank you!