I would like to see replications, as it could just be bad data:

"It is also possible that the long-term reduction in BMR represents methodological artefacts. In the early years, measurements of BMR were often made using mouthpieces to collect respiratory gases, and recently such devices have been shown to elevate BMR by around 6%. A second possibility is that early measurements paid less attention to controlling ambient temperature to ensure individuals were at thermoneutral temperatures."

Thanks for the link to this very strong and now open study.

The authors suggest that the decreased consumption of saturated fats over the last 30+ years is likely to contribute to the reduction in basal metabolic rate and gains in weight. The mouse model component of the study provides some support.

I'm not an expert on the literature, but I do know Bmr isn't a fixed number. It is a function of activity, muscle mass, and other factors.

It seems that a largely sedentary lifestyle free from exertion matches both.

It would be insightful to see the sensitivity analysis for BMR with respect to strength, activity, muscle mass, ect.

I know there is a body of data about environmental hormones and BMR, ect, but my understanding is that the impact is barely measurable with large sample sizes. I expect that it can't hold a candle to activity. In my personal experience, my BMR can easily modulate by 1000 calories based on body composition and behavior. That is a huge impact.

> Nevertheless, the solution is still the same: eat less.

Or make life harder! Quit the elevator. Quit the automatic transmission (and car). Quit the online shopping.

Making some progress with self-checkouts and pointless lineups at airports.

Less jokingly (hard to outrun a bad diet) but more pedanticly: drinking less (alcohol and calorific beverages) might be a better start than eating less.

It would be interesting to correlate these results with data about reduced testosteron levels and sperm counts/fertility, especially whether one of these leads the other or whether both go down at the same time.

lack of physical activity (sedentary job + sedentary entertainment) + shitty diet = lower testosterone

lower testosterone = lower lean body mass (you gain tens of pounds of muscle on TRT even without exercising)

lower lean body mass = lower BMR. an average doughy 200 pound guy and a 200 pound athlete have vastly different caloric requirements.