user4742: My question is mainly to monks and nuns in this group, but I welcome answers from others as well. 
If one were to give up eating solid food after the midday, as instructed by the Buddha to his Bhikkhu and Bhikkhuni, what practical advice would you give such a person in order to avoid getting gastritis and stomach ulcers?

user-1: One needs to chance his/her life and simply tries. To give certain advice that makes general sense for many in facing problems is not possible, and if wished to talk in personal, one may free to ask in way of talk, public or in areas where only practicing exchange personal things if wished, here given. 
It's how ever not a problem to keep parts or all eight precepts permanent for lay people.
Note also that there have been not given any advices or rules in detail to lay person by the Buddha, since such a practice actually can only be explained who do and there have been many, not so today.
So any commentaries are prepared from certain monk rules and do not really match the precept but are counteracts of problem in regard of tendencies in the Sangha at this time.
You may also talk to Upasaka Akila about feedback, who did such merits for a week successful some weeks ago, in way of respectul talk.
[Next time, you do good to generally approach Monks and Nuns proper]
(Note: This is a Gift of Dhamma and not meant for any commercial purpose or other worldly gain.)

user-1: I think you're worrying too much.  Not eating for 16 hours is really not that big a deal.  During times of scarcity, our forebears would go days between meals!  If you are looking for some practical advice, my inclination is to steer you towards the intermittent fasting community.  There are tons of people practicing this kind of diet albeit for health rather than spiritual concerns.  You are much more likely to find practical advice through that avenue than via the Buddhist community.    

user295: From what I think, stomach juices from if you keep thing about food or feel hungry.
Whenever hunger arises if you are equanimous then and do not have this lead to thoughts about food and food craving then your stomach will become inactive and also hunger will subside. You can use the sensation of hunger as an object of insight meditation. This is how I whether it you when I am in retreats.
Also when you are occupied there is tendency you feel hunger less. In such situation if thoughts about food does not arise I guess your body will not react by producing stomach juices.
Also one purpose of not eating after noon is to make time and also make practicing meditation easier. So if you are in mediation for most of the day you do not tend to get these issues. You do not burn much calories to get hungry. You would not be thinking about food. You would also had a lite diet.
Hunger is a flavor of aversion which you should try to avoid arising.

user254: This advice seems relevant (by a gastroenterologist and published in Canada's largest newspaper):

Fasting tips for those with gastritis and peptic ulcer


4742: <p>My question is mainly to monks and nuns in this group, but I welcome answers from others as well. </p>

<p>If one were to give up eating solid food after the midday, as instructed by the Buddha to his Bhikkhu and Bhikkhuni, what practical advice would you give such a person in order to avoid getting gastritis and stomach ulcers?</p>
 -1: <p>One needs to chance his/her life and simply tries. To give certain advice that makes general sense for many in facing problems is not possible, and if wished to talk in personal, one may free to ask in way of talk, public or in areas where only practicing exchange personal things if wished, <a href="http://sangham.net/index.php?action=forum" rel="nofollow noreferrer">here</a> given. </p>

<p>It's how ever not a problem to keep parts or all eight precepts permanent for lay people.</p>

<p>Note also that there have been not given any advices or rules in detail to lay person by the Buddha, since such a practice actually can only be explained who do and there have been many, not so today.
So any commentaries are prepared from certain monk rules and do not really match the precept but are counteracts of problem in regard of tendencies in the Sangha at this time.</p>

<p>You may also talk to Upasaka Akila about feedback, who did such merits for a week successful some weeks ago, in way of respectul talk.</p>

<p>[Next time, you do good to generally approach Monks and Nuns proper]</p>

<p><em>(Note: This is a Gift of Dhamma and not meant for any commercial purpose or other worldly gain.)</em></p>
 -1: <p>I think you're worrying too much.  Not eating for 16 hours is really not that big a deal.  During times of scarcity, our forebears would go days between meals!  If you are looking for some practical advice, my inclination is to steer you towards the intermittent fasting community.  There are tons of people practicing this kind of diet albeit for health rather than spiritual concerns.  You are much more likely to find practical advice through that avenue than via the Buddhist community.    </p>
 295: <p>From what I think, stomach juices from if you keep thing about food or feel hungry.</p>

<p>Whenever hunger arises if you are equanimous then and do not have this lead to thoughts about food and food craving then your stomach will become inactive and also hunger will subside. You can use the sensation of hunger as an object of insight meditation. This is how I whether it you when I am in retreats.</p>

<p>Also when you are occupied there is tendency you feel hunger less. In such situation if thoughts about food does not arise I guess your body will not react by producing stomach juices.</p>

<p>Also one purpose of not eating after noon is to make time and also make practicing meditation easier. So if you are in mediation for most of the day you do not tend to get these issues. You do not burn much calories to get hungry. You would not be thinking about food. You would also had a lite diet.</p>

<p>Hunger is a flavor of aversion which you should try to avoid arising.</p>
 254: <p>This advice seems relevant (by a gastroenterologist and published in Canada's largest newspaper):</p>

<ul>
<li><a href="http://www.thestar.com.my/lifestyle/health/nutrition/2013/07/10/fasting-tips-for-those-with-gastritis-and-peptic-ulcer-disease-during-ramadan/" rel="nofollow noreferrer">Fasting tips for those with gastritis and peptic ulcer</a></li>
</ul>
