Hungry as a Bear: What Predator’s 20,000 Calories-a-Day Diet Looks Like to Us

by Jon D. B.

One McDonalds Big Mac is 563 calories. Eat 36-to-40 Big Macs in one day and you’ll be on par with the American black bear’s ravenous hyperphagia.

You read that right! As autumn rolls on, bears enter their pre-winter feeding frenzy. Biologists call this hyperphagia: A period of excessive eating and drinking to fatten for hibernation.

This fancy word simply means that bears (like the blacks and browns of North America) are eating and drinking constantly throughout their day in order to prepare for winter hibernation. Nothing else matters in this timespan but food, more food, and water to wash it down.

Eat this pile of McDonalds 6-to-8 times and you’ll be on track to keep up with a hyperphagious bear. (Photo by Dominic Lipinski/PA Images via Getty Images)

The behavior correlates with a whole lot of bruin encounters, break-ins, and even human fatalities this time of year. In states like Tennessee and Colorado, black bears go into overdrive and can become overly mischievous in their ravenous search for food.

In fact, the North American Bear Center cites that black bears with unlimited food and water sources will eat 15,000 to 20,000 calories per day during hyperphagia. 20,000 calories is their bodies’ goal for every single 24-hour period. Imagine eating those 40 Big Macs every singe day for weeks on end, then sleeping for 4-to-7 months. Such is the life of a black bear.

Colorado Black Bears are in ‘Overdrive’ Before Hibernation

Over on Twitter, Colorado Parks & Wildlife has a startling visual aid for what 20,000 calories in one day would look like for us humans. Observe:

“Bears are in hyperphagia, the fall period when bruins are preparing for hibernation and spend up to 20 hours a day on the hunt for 20,000 or more daily calories,” the service captions their tweet.

“Compare that to 1-lb of berries, which is just 2,000 calories,” CPW’s NE Region continues. “Most conflicts between people & bears are traced to easy-to-get human food, garbage, pet food, bird seed, etc. When people allow bears to find food, a bear’s natural drive to eat can overcome its wariness of humans.”

CPW also includes a few other calorie comparisons for good measure:

  • Bird seed (7 lbs): 12,180 calories
  • Dog Food (25 lbs): 42,425 calories
  • Peanut Butter (28 oz): 4,750 calories
  • Shortening (3 lbs): 12,430 calories
A massive hyperphagious American black bear rests after packing on some serious pounds ahead of winter hibernation. (Photo Credit: Pacific Press/LightRocket via Getty Images)

As the examples above show, these calories don’t appear out of thin air. A bruin’s search for food can be grueling as Colorado’s 17,000 to 20,000 bruins contend over the same sources. This is exactly what leads to home/car break-ins and close-encounters. We are competition for the bruins, after all.

“Really, it’s a daily occurrence now: bears getting into vehicles that are unlocked, getting into houses that have their windows cracked,” CPW wildlife officer Chase Rylands told local WAVY recently.

It is paramount to know your bear safety and take all possible scenarios into account when living in Bear Country. This time of year, however, being “bear aware” is even more important. A much as we love our bruins, the species remains a large and very dangerous predator, and this stands doubly true as our bruin neighbors pack on the pounds for winter hibernation.