<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>jniedrauer</author><text>I can speak to this a bit. I practiced intermittent fasting (eating once per day) for nearly a decade, while maintaining a very low activity level. My resting metabolic rate dropped significantly during this time (down to about 1300 kcal&amp;#x2F;day).&lt;p&gt;About a year ago, I increased my activity level significantly (distance running, hiking, strength training, cycling) and quickly found that:&lt;p&gt;a) I wasn&amp;#x27;t recovering quickly enough&lt;p&gt;b) It was extremely difficult to take in enough calories for a day in a single meal&lt;p&gt;c) I had very low energy when in ketosis&lt;p&gt;Eventually I gave up and just started eating on a typical 3-4 meal a day schedule. My RMR steadily increased back to baseline, I got a lot more explosive energy, my body began responding much more rapidly to training, and my recovery speed improved significantly.&lt;p&gt;Personally I think that intermittent fasting is not a good idea if you are very physically active. That&amp;#x27;s just my opinion from my own experience.</text><parent_chain><item><author>kace91</author><text>Are you fit? as in, do you lift weights or are active in sports that require strength?&lt;p&gt;I ask because I wonder about the effects of extended fasts on muscle loss&amp;#x2F;retention, a big problem cutting weight for some people is that they  get rid of some muscle mass along with the calories they wanted to eliminate.</text></item><item><author>dvt</author><text>I fast, on average, once a week. At least once a month, I try to do an extended fast (2-5 days) to force ketosis. I also do intermittent fasting basically daily (I only eat between 12-8). Been doing this for about 4 years now. Some anecdata:&lt;p&gt;- Fasting &amp;gt; 24 hrs paradoxically gives you an extreme boost of energy and mental focus. I especially love how my olfactory sense is &lt;i&gt;extremely&lt;/i&gt; heightened. It&amp;#x27;s pretty cool and even after all these years doesn&amp;#x27;t get old.&lt;p&gt;- Fasting is not a panacea. Depriving yourself of nutrients or eating garbage is still a bad idea even if you fast or do IF. Unfortunately, eating healthy is hard and kinda&amp;#x27; sucks. Egg whites and chicken + broccoli gets old pretty fast.&lt;p&gt;- Fasting &amp;gt;7 days is a bad idea unless you know what you&amp;#x27;re doing.  This is when your muscles and vital organs start contributing as an energy source (e.g. they also start breaking down).&lt;p&gt;- Your body is clever, so extended fasts will start putting you into &amp;quot;starvation mode&amp;quot; and you&amp;#x27;ll lose some of the benefits.&lt;p&gt;- There have been NO STUDIES on long-term fasting (e.g. over the course of an adult lifetime). This is a big warning sign to just be careful and not overdo it. Different people have different tolerances. Talk to your doctor.&lt;p&gt;- Even on fast days, make sure you take vitamins (I take Fish Oil, Zinc, a Multivitamin and Magnesium)</text></item></parent_chain></comment><story><title>Alternate Day Fasting Improves Physiological and Molecular Markers of Aging [pdf]</title><url>https://www.cell.com/action/showPdf?pii=S1550-4131%2819%2930429-2</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>dvt</author><text>I did for a few months this year, but I&amp;#x27;ve been lazy over the summer. I&amp;#x27;m 155lb, 6&amp;#x27;0, so fairly skinny, maybe at around ~15% BF. I noticed that fasting doesn&amp;#x27;t help with BF at all unless I eat very clean and lift. I was at 170lb, around ~28% BF earlier this year and had to work my ass off to get my body fat percentage down.</text><parent_chain><item><author>kace91</author><text>Are you fit? as in, do you lift weights or are active in sports that require strength?&lt;p&gt;I ask because I wonder about the effects of extended fasts on muscle loss&amp;#x2F;retention, a big problem cutting weight for some people is that they  get rid of some muscle mass along with the calories they wanted to eliminate.</text></item><item><author>dvt</author><text>I fast, on average, once a week. At least once a month, I try to do an extended fast (2-5 days) to force ketosis. I also do intermittent fasting basically daily (I only eat between 12-8). Been doing this for about 4 years now. Some anecdata:&lt;p&gt;- Fasting &amp;gt; 24 hrs paradoxically gives you an extreme boost of energy and mental focus. I especially love how my olfactory sense is &lt;i&gt;extremely&lt;/i&gt; heightened. It&amp;#x27;s pretty cool and even after all these years doesn&amp;#x27;t get old.&lt;p&gt;- Fasting is not a panacea. Depriving yourself of nutrients or eating garbage is still a bad idea even if you fast or do IF. Unfortunately, eating healthy is hard and kinda&amp;#x27; sucks. Egg whites and chicken + broccoli gets old pretty fast.&lt;p&gt;- Fasting &amp;gt;7 days is a bad idea unless you know what you&amp;#x27;re doing.  This is when your muscles and vital organs start contributing as an energy source (e.g. they also start breaking down).&lt;p&gt;- Your body is clever, so extended fasts will start putting you into &amp;quot;starvation mode&amp;quot; and you&amp;#x27;ll lose some of the benefits.&lt;p&gt;- There have been NO STUDIES on long-term fasting (e.g. over the course of an adult lifetime). This is a big warning sign to just be careful and not overdo it. Different people have different tolerances. Talk to your doctor.&lt;p&gt;- Even on fast days, make sure you take vitamins (I take Fish Oil, Zinc, a Multivitamin and Magnesium)</text></item></parent_chain></comment><story><title>Alternate Day Fasting Improves Physiological and Molecular Markers of Aging [pdf]</title><url>https://www.cell.com/action/showPdf?pii=S1550-4131%2819%2930429-2</url></story>