Summary: Work has changed dramatically over time, shifting significantly from physical to mental labor. Today, office jobs demand far less physical energy and carry far lower risks of injury or death compared to physically demanding trades. This transition shows how progress has allowed us to create more value with less strain on our bodies—and with far greater safety than workers of the past could have imagined.

Economist George Gilder points out that using blue-collar hourly wage rates to calculate time prices underestimates the gains we’re enjoying in an economy that’s no longer driven by muscle but by mind. Knowledge workers earn more in an hour, consume fewer calories, and risk far less death or injury than other workers. In other words, they do far more with far less. This is the true compounding of progress—and we can see it mapped on a single chart.

Calories Per Hour of Work

I asked several AI models about the number of calories per hour that different kinds of work require and this is what I got:

The energy demands of physical work versus knowledge work reveals a dramatic difference in caloric expenditure. Workers in physically demanding jobs burn significantly more calories than do their office counterparts:

High-energy physical work:

• Construction tasks such as masonry or hanging sheetrock: 400–500 calories per hour (equivalent to running or high-intensity aerobics)
• Heavy lifting and transport: 285–300 calories per hour for a 170-pound worker

Moderate physical work:

• Manufacturing: 228 calories per hour (men), 180 calories per hour (women)

Office work:

• Standing desk: 186 calories per hour for a 170-pound person
• Sitting desk work: 100 calories per hour

As we transition from working with atoms to working with knowledge our bodies require a lot less energy to perform that work. Moving from construction work to sitting at a desk in an office requires 77.8 percent fewer calories per hour. Put another way, the calories needed to fuel one construction worker can power 4.5 office workers. The result is an economic system that creates more value with less resource consumption.

Fatal work injury rate

The Bureau of Labor Statistics reports on fatalities on the job:

Farming, fishing, and forestry are the most dangerous professions at 24.4 fatal injuries, with transportation and material moving at 13.6, and construction and extraction at 12.9. Office and administrative support are the least risky professions at 0.6. Farmers, fishermen, and loggers are more than 40 times likely than an office worker to be killed on the job. Moving from construction work to sitting at a desk in an office reduces the risk of a work fatality by 95.3 percent. Adjusted for population size, construction workers experience a work-related fatality rate more than 21 times higher than that of office workers.

And it was much worse in the past—something that we tend to forget when looking at present statistics. In 1900, deaths in the mining and oil extractions fields (lumped under mining) was estimated at 333 per 100,000 workers and remained that high through the 1920s. We can hardly comprehend just how good we’ve got it now.

Calorie-fatality index

If we combine these two factors into a calorie-fatality index and compare the construction and office industries, we note that office work is 99 percent lower than construction work on the index. Moving from blue-collar construction work to an office job indicates an overall improvement factor of 96.75 (or 9,575 percent) on the calorie-fatality index.

Find more of Gale’s work at his Substack, Gale Winds.

“In Indonesia … The rate of exclusive breastfeeding among infants under six months has steadily increased, rising from 52% in 2017 to 66.4% in 2024. However, many infants are not exclusively breastfed for the full six months – the duration required to achieve the full health benefits.”

From World Health Organization.

“We examine how consumers modify their food demand after adopting appetite-suppressing GLP-1 receptor agonists, such as Ozempic and Wegovy. Using survey responses on medication adoption and timing linked to transaction data from a representative U.S. household panel, we document the prevalence, motivations, and demographic patterns of GLP-1 adoption. Households with at least one GLP-1 user reduce grocery spending by 5.5% within six months of adoption, with higher-income households reducing spending by 8.6%. These reductions are driven by large decreases in purchases of calorie-dense, processed items, including an 11% decline in savory snacks. While most food categories see spending declines, spending on nutrient-dense options, such as yogurt and fresh produce, shows directionally positive but statistically insignificant changes. We also find an 8.6% decline in spending at fast-food chains, coffee shops, and limited-service restaurants.”

From Cornell SC Johnson College of Business.

“Kids ages 2 through 19 consumed an average of 11.4% of their daily calories from fast food on a given day between August 2021 and August 2023, according to data from the CDC’s National Health and Nutrition Examination Survey.

• That’s down from an average of nearly 14% in 2013 and 2014, per CDC data.
• For adults age 20 and up, average calories from fast food fell from about 14% in 2013 and 2014 to 11.7% during mid-2021 to mid-2023.
• Food reported as “restaurant fast food/pizza” on survey responses was considered fast food for these analyses, CDC’s data brief said.

Zoom out: About 30% of youth ages 2 through 19 ate fast food on any given day between August 2021 and 2023. That figure exceeded 36% between 2015 and 2018, CDC found.”

From Axios.