<story><title>When somebody loses weight, where does the fat go?</title><url>http://www.bmj.com/content/349/bmj.g7257</url></story><parent_chain><item><author>Zanta</author><text>From the paper &amp;quot;Replacing one hour of rest with exercise that raises the metabolic rate to seven times that of resting by, for example, jogging, removes an additional 39 g of carbon from the body, raising the total by about 20% to 240 g. For comparison, a single 100 g muffin represents about 20% of an average person’s total daily energy requirement. Physical activity as a weight loss strategy is, therefore, easily foiled by relatively small quantities of excess food.&amp;quot;</text></item><item><author>JoeAltmaier</author><text>Exercise makes more sense! Breathing hard == losing weight!</text></item><item><author>mikeash</author><text>For anyone coming straight to the comments looking for an answer to the question: it turns into CO2 (and a bit of water) and you breathe it out.&lt;p&gt;When you realize that you have to breathe out all the weight you lose, I think it gives you a bigger appreciation for how  difficult weight loss can be.</text></item></parent_chain><comment><author>StevePerkins</author><text>I can&amp;#x27;t help but groan at some of the &amp;quot;obvious&amp;quot; health and weight loss platitudes that get smugly thrown around.&lt;p&gt;&amp;quot;&lt;i&gt;Calories in, calories out!&lt;/i&gt;&amp;quot;&lt;p&gt;&amp;quot;&lt;i&gt;You can&amp;#x27;t outrun a bad diet!&lt;/i&gt;&amp;quot;&lt;p&gt;&amp;quot;&lt;i&gt;Weight is lost in the kitchen!&lt;/i&gt;&amp;quot;&lt;p&gt;Sure, things ultimately boil down to intake-vs-expenditure.  However, it IS more complicated than that &lt;i&gt;in practice&lt;/i&gt;.  As software developers, we complain when management makes decisions based on inadequate or poor metrics.  But likewise there so many more benefits to physical exercise that aren&amp;#x27;t captured by a diet and exercise tracking app.&lt;p&gt;During times when I&amp;#x27;ve been 100% sedentary for long periods, I experience &lt;i&gt;overwhelming&lt;/i&gt; cravings for sugar and crappy foods.  When I force myself to take up any consistent exercise, even just a 30 min walk in the morning or lunchtime... then the cravings subside and regular meals are sufficient.  This is fairly common.&lt;p&gt;Exercise has so many physical and mental health benefits.  But even just looking at weight management alone, exercise tends to ramp up your metabolism for hours after each exercise session.  Something that doesn&amp;#x27;t get captured by your tracker app or wearable gadget.&lt;p&gt;So often, when I hear somebody smugly minimizing the importance of exercise to health and weight management, it&amp;#x27;s a person who is too-clever-by-half.  They&amp;#x27;re constantly dabbling with soylent shakes or paleo&amp;#x2F;keto fad diets... because the truth is they&amp;#x27;re just lazy and don&amp;#x27;t want to get off their ass, and look to rationalize that.&lt;p&gt;EDIT:  At least half of these replies are completely missing my point altogether.  I&amp;#x27;m not saying that there is a binary choice to be made between &amp;quot;good diet&amp;quot; OR &amp;quot;exercise&amp;quot;, and that you should make the latter choice rather than the former.  I&amp;#x27;m saying that &lt;i&gt;treating this as a binary choice in the first place&lt;/i&gt; is ridiculous.&lt;p&gt;Exercise &lt;i&gt;correlates&lt;/i&gt; with proper eating, it&amp;#x27;s not incidental or ancillary.  It&amp;#x27;s ineffective to tell someone to &amp;quot;go the gym&amp;quot; without changing their eating habits?  Well sure, but telling them to &amp;quot;go keto&amp;quot; without worrying about physical activity will be no more successful a year out.  It&amp;#x27;s the pretense that most people can consistently stick with one of these things, and not both together, that is absurd.</text></comment>
<story><title>When somebody loses weight, where does the fat go?</title><url>http://www.bmj.com/content/349/bmj.g7257</url></story><parent_chain><item><author>Zanta</author><text>From the paper &amp;quot;Replacing one hour of rest with exercise that raises the metabolic rate to seven times that of resting by, for example, jogging, removes an additional 39 g of carbon from the body, raising the total by about 20% to 240 g. For comparison, a single 100 g muffin represents about 20% of an average person’s total daily energy requirement. Physical activity as a weight loss strategy is, therefore, easily foiled by relatively small quantities of excess food.&amp;quot;</text></item><item><author>JoeAltmaier</author><text>Exercise makes more sense! Breathing hard == losing weight!</text></item><item><author>mikeash</author><text>For anyone coming straight to the comments looking for an answer to the question: it turns into CO2 (and a bit of water) and you breathe it out.&lt;p&gt;When you realize that you have to breathe out all the weight you lose, I think it gives you a bigger appreciation for how  difficult weight loss can be.</text></item></parent_chain><comment><author>misterdata</author><text>The question is whether the body spends any energy outside of that hour after exercising (e.g. by growing muscle, etc.) than it would otherwise. That would make exercise more effective when considering longer periods of time.</text></comment>