user-1: I recall reading, though I do not remember where, that jains and buddhists refrain from masturbation because it could cancel/hinder their spiritual progress. I somewhat wonder: 
Does engaging in coarse pleasures as gluttonous eating or sexuality actively undo spiritual progress and virtue, or does it merely consist as a distraction and waste of time? 
Thank you

user471: The following quote comes from "Chapter Six: Daily Life" of Yuttadhammo Bhikkhu's book entitled "How To Meditate".
Basically, the five precepts are an absolute must at all times for seriously practising lay persons and monks. Without them, your spiritual progress and virtue would be strongly hindered and possibly also undone. In this case, complete abstention is required.
On the other hand, overeating, oversleeping, too much entertainment and too much sex (without misconduct) are not as critical as the five precepts, though they would be a hindrance nevertheless. In this case, only moderation is required for a lay person, not complete abstention.
In addition, observance of the eight precepts from time to time is also recommended. This is the usual observance for meditation retreats.

First, it is necessary to discuss activities that are harmful to one’s
  mental clarity; activities one must avoid in order for the meditation
  to bring about sustained positive results.
As I explained in the first chapter, “meditation” is the mental
  equivalent to “medicine”. When taking medicine, there are certain
  substances one must avoid; substances that will either nullify the
  positive effects of the medicine or, worse, combine with the medicine
  to create poison. Likewise, with meditation there are certain
  activities that, due to their tendency to cloud the mind, have the
  potential to nullify the effects of the meditation or, worse, pervert
  one’s understanding of the meditation, causing one to cultivate
  unwholesome mind states instead of wholesome ones.
Meditation is meant to cultivate clarity and understanding, free from
  addiction, aversion, and delusion, and therefore free from suffering.
  Since certain bodily and verbal acts are intrinsically tied to
  negative qualities of mind, they are considered ‘contraindicative’ to
  the meditation practice; they have an effect opposite to what is
  desired, cultivating defilement instead of purity. Meditators who
  insist on engaging in such behaviour will face great difficulty in
  their practice, developing habits that are detrimental to both
  meditation practice and personal well-being. To ensure the mind is
  perfectly clear and capable of understanding reality, certain
  behaviours must be taken out of one’s “diet”, so to speak.
First, there are five kinds of action from which one must refrain
  completely, as they are inherently unwholesome:

One must refrain from killing living beings. In order to cultivate one’s own well-being, one must be dedicated to well-being as a
  principle, refraining from killing any living being, even ants,
  mosquitoes and other living beings.
One must refrain from theft. In order to find peace of mind, we must grant it to others as well; stealing is a denial of this basic
  right to security. Further, if we wish to be free from addiction, we
  must be able to control our desires to the extent of respecting the
  possessions of others.
One must abstain from committing adultery or sexual misconduct. Romantic relationships that are emotionally or spiritually damaging to
  others, due to existing commitments of the parties involved, are a
  cause for stress and suffering and based on perversion of the mind.
One must refrain from telling lies. If one wishes to find truth, one must avoid falsehood; intentionally leading others away from the
  truth is harmful both to oneself and others and incompatible with the
  goals of meditation.
One must refrain from taking drugs or alcohol. Any substance that intoxicates the mind is obviously contraindicative to meditation
  practice, as it is the antithesis of a natural, clear state of being.

Complete abstention from these activities is necessary if one wishes
  for meditation practice to be successful, due to their inherently
  unwholesome nature and the invariably negative effect they have on the
  mind.
Further, there are certain activities that must be moderated or they
  will interfere with meditation practice. These are activities that are
  not necessarily unwholesome in and of themselves but will nonetheless
  inhibit clarity of mind and lessen the benefit of the meditation
  practice when undertaken in excess.
One such activity is eating; if one wishes to truly progress in the
  meditation practice, one must be careful not to eat too much or too
  little. If one is constantly obsessed with food, it can be a great
  hindrance to progress in meditation since not only does it cloud the
  mind, over-eating leads to drowsiness, both in the body and mind. One
  should eat to stay alive rather than stay alive simply to eat. During
  intensive meditation courses, meditators eat one main meal per day and
  suffer no negative physical consequences as a result; whereas the
  positive effects of such moderation are clarity of mind and freedom
  from obsession over food.
Another activity that interferes with meditation practice is
  entertainment – watching movies, listening to music, and so on. These
  occupations are not inherently unwholesome but can easily create
  states of addiction when undertaken in excess.
Addiction is a form of insobriety in a sense, since it involves
  chemical processes in the brain that inhibit clear thought and clarity
  of mind. Since the pleasure that comes from entertainment is momentary
  and unsatisfying while the addiction and obsession carry over into
  one’s life, a serious meditator should determine to make the best use
  of their short time in this life by cultivating peace and contentment,
  rather than wasting it on meaningless activities that don’t lead to
  long term happiness and peace. If one wishes to find true happiness,
  one must therefore moderate one’s engagement in entertainment.
  Socializing on the Internet and similar activities should be
  undertaken in moderation as well.
The third activity one must moderate is that of sleeping. Sleeping is
  an addiction that is often overlooked; most people don’t realize how
  attached they are to sleep as a means of escape from reality. Still
  others become insomniac, obsessed with the thought that they are not
  getting “enough” sleep, leading to increased stress levels and further
  difficulty in falling asleep.
Through the meditation practice, one will find that one needs less
  sleep than before since one’s mind will become calmer. Insomnia is not
  a problem for meditators since they are able to meditate even in the
  lying position and keep their minds free from stress. People who have
  difficulty falling asleep should train themselves to watch the stomach
  rise and fall, noting “rising”, “falling”, all night if necessary.
  Even if they are not able to fall asleep (which is unlikely, given the
  calm state of mind while meditating) they will find themselves as
  rested as if they had slept soundly through the night.
Finally, it is worth mentioning that to truly gain results in the
  meditation practice, a meditator should set aside at least a period of
  time to remain entirely celibate, not just avoiding immoral sexual
  activity, since all sexual activity is invariably intoxicating and
  will be a hindrance towards attainment of mental clarity and peace.


user13694: The mind is an organ of habits and reactions. Those habits and reactions appear after sense contact, and it is based on the before learnt patterns of the mind. In turn, those patterns become ingrained due to repeated intentional behavior.
What I just mentioned is a -shallow- summary of kamma (intentional deeds) and the effect on the mind, in short and long term. 
It's hard to know when will the mind establish a pattern, and when that pattern will become an habitual tendency, which is the source of habitual reactions and responses.
The mind is like a glass of water, but we don't know how filled it is. That's why we should be wise, prudent and cautious, because we don't know how much water does it take to overflow that glass; maybe it takes a lot of it, or maybe a few drops. 
We don't know when our past actions will gave fruition to their consequences. We don't know exactly how the past kamma has influenced our minds and our habits/responses. We don't know for sure how will a new act affect our past kammic story.
In the Dvedhavitakka Sutta, it is said:

"Whatever a monk keeps pursuing with his thinking & pondering, that
  becomes the inclination of his awareness. If a monk keeps pursuing
  thinking imbued with sensuality, abandoning thinking imbued with
  renunciation, his mind is bent by that thinking imbued with
  sensuality. If a monk keeps pursuing thinking imbued with ill will,
  abandoning thinking imbued with non-ill will, his mind is bent by that
  thinking imbued with ill will. If a monk keeps pursuing thinking
  imbued with harmfulness, abandoning thinking imbued with harmlessness,
  his mind is bent by that thinking imbued with harmfulness."

https://www.accesstoinsight.org/tipitaka/mn/mn.019.than.html
Have a wonderful day!

-1: <p>I recall reading, though I do not remember where, that jains and buddhists refrain from masturbation <em>because it could cancel/hinder their spiritual progress.</em> I somewhat wonder: </p>

<p><strong>Does engaging in coarse pleasures as gluttonous eating or sexuality actively <em>undo</em> spiritual progress and virtue, or does it merely consist as a distraction and waste of time?</strong> </p>

<p>Thank you</p>
 471: <p>The following quote comes from "<a href="https://www.sirimangalo.org/text/how-to-meditate/chapter-six-daily-life/" rel="nofollow noreferrer">Chapter Six: Daily Life</a>" of Yuttadhammo Bhikkhu's book entitled "<a href="https://www.sirimangalo.org/text/how-to-meditate/" rel="nofollow noreferrer">How To Meditate</a>".</p>

<p>Basically, the <a href="https://www.accesstoinsight.org/ptf/dhamma/sila/pancasila.html" rel="nofollow noreferrer">five precepts</a> are an absolute must at all times for seriously practising lay persons and monks. Without them, your spiritual progress and virtue would be strongly hindered and possibly also undone. In this case, complete abstention is required.</p>

<p>On the other hand, overeating, oversleeping, too much entertainment and too much sex (without misconduct) are not as critical as the five precepts, though they would be a hindrance nevertheless. In this case, only moderation is required for a lay person, not complete abstention.</p>

<p>In addition, observance of the <a href="https://www.accesstoinsight.org/ptf/dhamma/sila/atthasila.html" rel="nofollow noreferrer">eight precepts</a> from time to time is also recommended. This is the usual observance for meditation retreats.</p>

<blockquote>
  <p>First, it is necessary to discuss activities that are harmful to one’s
  mental clarity; activities one must avoid in order for the meditation
  to bring about sustained positive results.</p>
  
  <p>As I explained in the first chapter, “meditation” is the mental
  equivalent to “medicine”. When taking medicine, there are certain
  substances one must avoid; substances that will either nullify the
  positive effects of the medicine or, worse, combine with the medicine
  to create poison. Likewise, with meditation there are certain
  activities that, due to their tendency to cloud the mind, have the
  potential to nullify the effects of the meditation or, worse, pervert
  one’s understanding of the meditation, causing one to cultivate
  unwholesome mind states instead of wholesome ones.</p>
  
  <p>Meditation is meant to cultivate clarity and understanding, free from
  addiction, aversion, and delusion, and therefore free from suffering.
  Since certain bodily and verbal acts are intrinsically tied to
  negative qualities of mind, they are considered ‘contraindicative’ to
  the meditation practice; they have an effect opposite to what is
  desired, cultivating defilement instead of purity. Meditators who
  insist on engaging in such behaviour will face great difficulty in
  their practice, developing habits that are detrimental to both
  meditation practice and personal well-being. To ensure the mind is
  perfectly clear and capable of understanding reality, certain
  behaviours must be taken out of one’s “diet”, so to speak.</p>
  
  <p>First, there are five kinds of action from which one must refrain
  completely, as they are inherently unwholesome:</p>
  
  <ol>
  <li><p>One must refrain from killing living beings. In order to cultivate one’s own well-being, one must be dedicated to well-being as a
  principle, refraining from killing any living being, even ants,
  mosquitoes and other living beings.</p></li>
  <li><p>One must refrain from theft. In order to find peace of mind, we must grant it to others as well; stealing is a denial of this basic
  right to security. Further, if we wish to be free from addiction, we
  must be able to control our desires to the extent of respecting the
  possessions of others.</p></li>
  <li><p>One must abstain from committing adultery or sexual misconduct. Romantic relationships that are emotionally or spiritually damaging to
  others, due to existing commitments of the parties involved, are a
  cause for stress and suffering and based on perversion of the mind.</p></li>
  <li><p>One must refrain from telling lies. If one wishes to find truth, one must avoid falsehood; intentionally leading others away from the
  truth is harmful both to oneself and others and incompatible with the
  goals of meditation.</p></li>
  <li><p>One must refrain from taking drugs or alcohol. Any substance that intoxicates the mind is obviously contraindicative to meditation
  practice, as it is the antithesis of a natural, clear state of being.</p></li>
  </ol>
  
  <p>Complete abstention from these activities is necessary if one wishes
  for meditation practice to be successful, due to their inherently
  unwholesome nature and the invariably negative effect they have on the
  mind.</p>
  
  <p>Further, there are certain activities that must be moderated or they
  will interfere with meditation practice. These are activities that are
  not necessarily unwholesome in and of themselves but will nonetheless
  inhibit clarity of mind and lessen the benefit of the meditation
  practice when undertaken in excess.</p>
  
  <p>One such activity is eating; if one wishes to truly progress in the
  meditation practice, one must be careful not to eat too much or too
  little. If one is constantly obsessed with food, it can be a great
  hindrance to progress in meditation since not only does it cloud the
  mind, over-eating leads to drowsiness, both in the body and mind. One
  should eat to stay alive rather than stay alive simply to eat. During
  intensive meditation courses, meditators eat one main meal per day and
  suffer no negative physical consequences as a result; whereas the
  positive effects of such moderation are clarity of mind and freedom
  from obsession over food.</p>
  
  <p>Another activity that interferes with meditation practice is
  entertainment – watching movies, listening to music, and so on. These
  occupations are not inherently unwholesome but can easily create
  states of addiction when undertaken in excess.</p>
  
  <p>Addiction is a form of insobriety in a sense, since it involves
  chemical processes in the brain that inhibit clear thought and clarity
  of mind. Since the pleasure that comes from entertainment is momentary
  and unsatisfying while the addiction and obsession carry over into
  one’s life, a serious meditator should determine to make the best use
  of their short time in this life by cultivating peace and contentment,
  rather than wasting it on meaningless activities that don’t lead to
  long term happiness and peace. If one wishes to find true happiness,
  one must therefore moderate one’s engagement in entertainment.
  Socializing on the Internet and similar activities should be
  undertaken in moderation as well.</p>
  
  <p>The third activity one must moderate is that of sleeping. Sleeping is
  an addiction that is often overlooked; most people don’t realize how
  attached they are to sleep as a means of escape from reality. Still
  others become insomniac, obsessed with the thought that they are not
  getting “enough” sleep, leading to increased stress levels and further
  difficulty in falling asleep.</p>
  
  <p>Through the meditation practice, one will find that one needs less
  sleep than before since one’s mind will become calmer. Insomnia is not
  a problem for meditators since they are able to meditate even in the
  lying position and keep their minds free from stress. People who have
  difficulty falling asleep should train themselves to watch the stomach
  rise and fall, noting “rising”, “falling”, all night if necessary.
  Even if they are not able to fall asleep (which is unlikely, given the
  calm state of mind while meditating) they will find themselves as
  rested as if they had slept soundly through the night.</p>
  
  <p>Finally, it is worth mentioning that to truly gain results in the
  meditation practice, a meditator should set aside at least a period of
  time to remain entirely celibate, not just avoiding immoral sexual
  activity, since all sexual activity is invariably intoxicating and
  will be a hindrance towards attainment of mental clarity and peace.</p>
</blockquote>
 13694: <p>The mind is an organ of habits and reactions. Those habits and reactions appear after sense contact, and it is based on the before learnt patterns of the mind. In turn, those patterns become ingrained due to repeated intentional behavior.</p>

<p>What I just mentioned is a -shallow- summary of kamma (intentional deeds) and the effect on the mind, in short and long term. </p>

<p>It's hard to know when will the mind establish a pattern, and when that pattern will become an habitual tendency, which is the source of habitual reactions and responses.</p>

<p>The mind is like a glass of water, but we don't know how filled it is. That's why we should be wise, prudent and cautious, because we don't know how much water does it take to overflow that glass; maybe it takes a lot of it, or maybe a few drops. </p>

<p>We don't know when our past actions will gave fruition to their consequences. We don't know exactly how the past kamma has influenced our minds and our habits/responses. We don't know for sure how will a new act affect our past kammic story.</p>

<p>In the Dvedhavitakka Sutta, it is said:</p>

<blockquote>
  <p>"Whatever a monk keeps pursuing with his thinking &amp; pondering, that
  becomes the inclination of his awareness. If a monk keeps pursuing
  thinking imbued with sensuality, abandoning thinking imbued with
  renunciation, his mind is bent by that thinking imbued with
  sensuality. If a monk keeps pursuing thinking imbued with ill will,
  abandoning thinking imbued with non-ill will, his mind is bent by that
  thinking imbued with ill will. If a monk keeps pursuing thinking
  imbued with harmfulness, abandoning thinking imbued with harmlessness,
  his mind is bent by that thinking imbued with harmfulness."</p>
</blockquote>

<p><a href="https://www.accesstoinsight.org/tipitaka/mn/mn.019.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/mn/mn.019.than.html</a></p>

<p>Have a wonderful day!</p>
