10. The grunt work of metabolic processes is done by enzymes. These proteins act like crowd control, ensuring molecules reacting catabolically or anabolically are where they need to be.
11. The enzymes themselves are constantly losing stability and being replaced, which means metabolism is a product of … metabolism. Whoa.
12. Metabolic diseases, which are typically genetic, cause the body to produce one or more enzymes insufficiently or not at all. Metabolic syndrome (MetS), however, is a more complex constellation of conditions.
13. MetS factors include increased abdominal fat, high blood pressure, insulin resistance, abnormal blood coagulation and cholesterol levels as well as elevated C-reactive protein, an indicator of inflammation.
14. The causes of MetS are not fully clear, but genes, inactivity and obesity all play a role, leading to significantly elevated risk of heart disease, diabetes and death.
15. We all know that being active and fit will make us healthier — and we’ve all heard the sales pitches that we can achieve that goal by revving up our metabolism with certain foods. Scientific support for many marketing claims is mixed, however.
16. Green tea extract, for example, has been shown to increase energy expenditure in some studies, possibly by inhibiting certain enzymes. A 2011 meta-analysis, however, found that the modest results varied both by individual and origin of extract used.
17. A 2012 review showed that green tea’s boost is even more of a bust: Its use resulted in “statistically insignificant” weight loss and no significant effect on weight management.
18. And sorry, but your metabolism will never match that of the ruby-throated hummingbird, which has the highest metabolic rate of any vertebrate when active.
19. To maintain body temperature and beat its wings up to 200 times a second, the metabolic record-setter, like other hummingbirds, needs enormous amounts of energy. The small birds typically consume their body weight in nectar every day. So much for thinking you can diet by “eating like a bird.”
20. On the other hand, in 2016 researchers found that the three-toed sloth had the lowest metabolic rate of any mammal, an adaptation that evolved to reduce fuel needs in the energy-poor forest canopy environment where it lives. Slothfulness isn’t one of the seven deadly sins — it’s just smart evolutionary strategy.