If you’ve ever tracked your food (calorie) intake with someone else, especially someone much larger or smaller than you, you may have been surprised to learn that the larger of the two of you could eat more and still lose weight. Why is that? Larger people are carrying their own body weight, everywhere they go. Consider two people of the same height, one weighing 120 lbs, and the other weighing 180 lbs. How exhausting would it be for the lighter person to carry 60 extra pounds (in a backpack, for example) all day long? Of course, the heavier person is accustomed to the extra weight, so carrying 180 lbs doesn’t feel strenuous, but the heavier person still burns more energy, or calories. There’s a good chance the heavier person is less active than the smaller person, but even factoring that in, the smaller person burns less energy.
When we are assessing jobs, this fact becomes important. There are guidelines for how much energy workers should exert in a day, and we need to consider the folks who will exert the most. If we design or evaluate based on a large worker, then smaller workers will be at lower risk.
Many people work under heat stress conditions during the summer. When it’s hot and humid, employers are required to give workers rest breaks to prevent heat-related illness. As the temperature and humidity increase, the need for rest also increases. And workers in “heavy” jobs need more rest than workers in “light” jobs. Our ergonomists measure job demands and use software to estimate how many calories a “large” worker would use on key jobs in client facilities, so the employer can ensure that workers are provided with the appropriate amount of rest. If the large worker is protected, then smaller workers will also be safe, since they use less energy.
I’m still following my New Year’s resolution, trying to take off my covid pounds. I’m almost tempted to strap on a backpack and carry around the weight that I’ve lost so far. Otherwise, the amount of food I’m allowed each day will continue to shrink….just the type of experiment that an ergo-nerd like me would think up!
If you’re overhauling your heat stress prevention program this year, NOW is the time to get your energy expenditure assessments done. Heat stress prevention is best planned while the weather is cool!