<story><title>Little kids burn so much energy, they’re like a different species, study finds</title><url>https://www.sciencemag.org/news/2021/08/little-kids-burn-so-much-energy-they-re-different-species-study-finds</url></story><parent_chain><item><author>tw04</author><text>This seems almost unbelievable to me. Almost everyone I know, with a handful of exceptions I can think of, had a dramatic change in what I can only say was metabolism at 30 declining steeply to 40.  I can tell you personally my ability to lose weight when exercising daily has decreased significantly since 30.  If it’s not metabolism, then what?  Diet and exercise are almost identical.</text></item><item><author>Supersam654</author><text>Personally, I was more surprised by the various groups of people who _don&amp;#x27;t_ have higher metabolic rates:&lt;p&gt;&amp;gt; Children’s metabolic rates stay high until age 5, but the rate slowly begins to glide down until it plateaus around age 20. Interestingly, adult rates are stable until age 60, when they begin to decline. After age 90, humans use about 26% less energy daily, Pontzer says.&lt;p&gt;&amp;gt; The study also found that pregnant women don’t have higher metabolic rates than other adults; their energy use and calorie consumption scales up with body size&lt;p&gt;&amp;gt; The metabolic rate didn’t zoom up in hungry teenagers either</text></item></parent_chain><comment><author>hansvm</author><text>Without more details if be inclined to blame &amp;quot;almost identical&amp;quot; as the culprit (not an expert):&lt;p&gt;Making all your meals 5% bigger would cause a weight gain of nearly 10lbs&amp;#x2F;yr, and the kind of switch in diet that can happen naturally with age (especially including eating out more with friends) can make it hard to spot incremental changes.&lt;p&gt;Moreover, a lot of exercise doesn&amp;#x27;t actually do much for weight loss (it&amp;#x27;s still immensely beneficial for your health; please don&amp;#x27;t stop). To counteract the aforementioned 10lbs&amp;#x2F;yr you&amp;#x27;d have to walk an extra ~20 minutes per day. It isn&amp;#x27;t all that much per se, but if your exercise were 20 minutes of something high intensity and an hour of something low intensity every single day (a lot more than most people get) it&amp;#x27;d still be a noticeable demand on your time -- enough that I don&amp;#x27;t think you&amp;#x27;d call the extra exercise level &amp;quot;nearly identical.&amp;quot;&lt;p&gt;It&amp;#x27;s also possible less visible culprits exist if you&amp;#x27;re used to average weight gains&amp;#x2F;losses of under a pound per month as a function of your diet&amp;#x2F;activity. E.g., iirc fidgiting and tapping your feet consumes nearly a pound per month in calories, and that doesn&amp;#x27;t seem like the kind of thing you&amp;#x27;d recognize stopping&amp;#x2F;starting over a timespan of decades.</text></comment>
<story><title>Little kids burn so much energy, they’re like a different species, study finds</title><url>https://www.sciencemag.org/news/2021/08/little-kids-burn-so-much-energy-they-re-different-species-study-finds</url></story><parent_chain><item><author>tw04</author><text>This seems almost unbelievable to me. Almost everyone I know, with a handful of exceptions I can think of, had a dramatic change in what I can only say was metabolism at 30 declining steeply to 40.  I can tell you personally my ability to lose weight when exercising daily has decreased significantly since 30.  If it’s not metabolism, then what?  Diet and exercise are almost identical.</text></item><item><author>Supersam654</author><text>Personally, I was more surprised by the various groups of people who _don&amp;#x27;t_ have higher metabolic rates:&lt;p&gt;&amp;gt; Children’s metabolic rates stay high until age 5, but the rate slowly begins to glide down until it plateaus around age 20. Interestingly, adult rates are stable until age 60, when they begin to decline. After age 90, humans use about 26% less energy daily, Pontzer says.&lt;p&gt;&amp;gt; The study also found that pregnant women don’t have higher metabolic rates than other adults; their energy use and calorie consumption scales up with body size&lt;p&gt;&amp;gt; The metabolic rate didn’t zoom up in hungry teenagers either</text></item></parent_chain><comment><author>epage</author><text>I can&amp;#x27;t say for the cases you named but its easy to overlook small lifestyle changes, like how much someone walked in college vs after.  That was one shift for me.</text></comment>