Yoma No.7: Day of Eatonement
יוֹם הַכִּפּוּרִים אָסוּר בַּאֲכִילָה וּבִשְׁתִיָּה וּבִרְחִיצָה וּבְסִיכָה וּבִנְעִילַת הַסַּנְדָּל, וּבְתַשְׁמִישׁ הַמִּטָּה. וְהַמֶּלֶךְ וְהַכַּלָּה יִרְחֲצוּ אֶת פְּנֵיהֶם, וְהַחַיָּה תִּנְעוֹל אֶת הַסַּנְדָּל, דִּבְרֵי רַבִּי אֱלִיעֶזֶר. וַחֲכָמִים אוֹסְרִין.
MISHNA: On Yom Kippur, the day on which there is a mitzva by Torah law to afflict oneself, it is prohibited to engage in eating and in drinking, and in bathing, and in smearing oil on one’s body, and in wearing shoes, and in conjugal relations. However, the king, in deference to his eminence, and a new bride within thirty days of her marriage, who wishes to look especially attractive at the beginning of her relationship with her husband, may wash their faces on Yom Kippur. A woman after childbirth, who is suffering, may wear shoes because going barefoot causes her pain. This is the statement of Rabbi Eliezer. The Rabbis prohibit these activities for a king, a new bride, and a woman after childbirth.

Jewish Americans in 2020, "Jewish practices and customs"

Pew Research Center

source

(ה) וּשְׁמַרְתֶּ֤ם אֶת־חֻקֹּתַי֙ וְאֶת־מִשְׁפָּטַ֔י אֲשֶׁ֨ר יַעֲשֶׂ֥ה אֹתָ֛ם הָאָדָ֖ם וָחַ֣י בָּהֶ֑ם אֲנִ֖י יְהֹוָֽה׃ {ס}
(5) You shall keep My laws and My rules, by the pursuit of which man shall live: I am the LORD.
גְּמָ׳ אָסוּר?! עָנוּשׁ כָּרֵת הוּא! אָמַר רַבִּי אִילָא, וְאִיתֵּימָא רַבִּי יִרְמְיָה: לֹא נִצְרְכָה אֶלָּא לַחֲצִי שִׁיעוּר.
GEMARA: The Gemara expresses surprise at the mishna’s terminology, which states that it is prohibited to eat and drink on Yom Kippur. Why does the mishna use the word prohibited, which indicates that these activities are only sinful? It is, after all, punishable by karet if he eats, and the mishna should have used the more accurate word liable. Rabbi Ila said, and some say that Rabbi Yirmeya said: This term is needed only for a half-measure, meaning that if one eats less than the amount that incurs the punishment of karet, he still violates a prohibition.

Hungry to be Heard

The Young Leadership Cabinet of the Orthodox Union developed a documentary, "Hungry to be Heard", focusing on the rising rates of anorexia, bulimia, and other eating disorders in our community. It aims at providing educational awareness, prevention, and approaches to eating disorders and is available for guided screenings as part of a conference, communal program, or as a stand-alone presentation.

דְּאִיתְּמַר חֲצִי שִׁיעוּר, רַבִּי יוֹחָנָן אָמַר: אָסוּר מִן הַתּוֹרָה, רֵישׁ לָקִישׁ אָמַר: מוּתָּר מִן הַתּוֹרָה. הָנִיחָא לְרַבִּי יוֹחָנָן, אֶלָּא לְרֵישׁ לָקִישׁ מַאי אִיכָּא לְמֵימַר? מוֹדֶה רֵישׁ לָקִישׁ שֶׁאָסוּר מִדְּרַבָּנַן.
The Gemara explains: as it was stated that amora’im debated the nature of a half-measure of a forbidden substance: Rabbi Yoḥanan said: It is prohibited by Torah law, and the Torah prohibits even a minute amount of forbidden substance. Reish Lakish said: It is permitted by Torah law. This explanation works out well according to the opinion of Rabbi Yoḥanan. However, according to the opinion of Reish Lakish, what can be said? The Gemara answers: Reish Lakish concedes that a half-measure is prohibited by rabbinic law. If so, Reish Lakish, too, will say that eating or drinking a half-measure is prohibited on Yom Kippur, by rabbinic law.

Wait 9 minutes between eating

Chabad article that explains the procedure one should follow if they have to eat on a fast

(Please note this is a general rule and a doctor should be consulted on a case by case basis)

What is the procedure for one who must eat on Yom Kippur?
Naftali Silberberg

"If possible, the ill person who must break the fast should eat and drink less than the abovementioned amount at intermittent intervals. Preferably, one should wait nine minutes between these snacks. Obviously, if the medical condition does not allow for this intermittent snacking, the patient must follow the doctor's orders."

(ט) (ט) שיהא מלא וכו' - ואף שרגיל לישפך קצת עי"ז לארץ ויש שאין ממלאין אותו כ"כ מטעם זה ואפ"ה שם מלא עליו. ודע דמלא הוא רק למצוה לכתחלה ואינו מעכב אם אך יש בהיין שיעור רביעית וכמו שכתבתי בסימן רע"א במ"ב סקמ"ב עי"ש:

תָּנוּ רַבָּנַן: ״תְּעַנּוּ אֶת נַפְשׁוֹתֵיכֶם״, יָכוֹל יֵשֵׁב בַּחַמָּה אוֹ בַּצִּנָּה כְּדֵי שֶׁיִּצְטַעֵר — תַּלְמוּד לוֹמַר: ״וְכׇל מְלָאכָה לֹא תַעֲשׂוּ״. מָה מְלָאכָה שֵׁב וְאַל תַּעֲשֶׂה, אַף עִנּוּי נֶפֶשׁ שֵׁב וְאַל תַּעֲשֶׂה.
§ After clarifying the wording of the mishna, the Gemara brings a halakhic midrash to analyze the mishna’s laws. The Sages taught: The verse states: “And this shall be a statute to you forever: In the seventh month on the tenth day of the month you shall afflict your souls” (Leviticus 16:29). I might have thought that one should sit in the sun or in the cold to suffer and afflict his soul; therefore the continuation of the verse states: “And you shall not do any labor, the home-born, or the stranger that lives among you” (Leviticus 16:29). This teaches that just as prohibited labor is a mitzva that requires one to sit and do nothing, as one is commanded to refrain from action, so too, affliction of one’s soul is also a mitzva requiring one to sit and do nothing. One is not commanded to be proactive in order to afflict his soul. Rather, one must refrain from specified actions such as eating and drinking.
מַתְנִי׳ הַתִּינוֹקוֹת אֵין מְעַנִּין אוֹתָן בְּיוֹם הַכִּפּוּרִים, אֲבָל מְחַנְּכִין אוֹתָן לִפְנֵי שָׁנָה וְלִפְנֵי שְׁנָתַיִים, בִּשְׁבִיל שֶׁיִּהְיוּ רְגִילִין בְּמִצְוֹת.
MISHNA: With regard to the children, one does not afflict them by withholding food on Yom Kippur; however, one trains them one year before or two years before they reach majority, by means of a partial fast lasting several hours, so that they will be accustomed to fulfill mitzvot.

Intuitive Eating

Evelyn Tribole and Elyse Resch

We've all been there―angry with ourselves for overeating, for our lack of willpower, for failing at yet another diet. But the problem is not us; it's that dieting, with its emphasis on rules and regulations, has stopped us from listening to our bodies.

Check out: Kids Eat in Color on Instagram

אָמַר רַב יוֹסֵף: מִכָּאן רֶמֶז לְסוֹמִין, שֶׁאוֹכְלִין וְאֵין שְׂבֵעִין. אָמַר אַבָּיֵי: הִלְכָּךְ, מַאן דְּאִית לֵיהּ סְעוֹדְתָּא לָא לֵיכְלַהּ אֶלָּא בִּימָמָא. אֲמַר רַבִּי זֵירָא, מַאי קְרָא: ״טוֹב מַרְאֵה עֵינַיִם מֵהֲלׇךְ נָפֶשׁ״. אָמַר רֵישׁ לָקִישׁ: טוֹב מַרְאֵה עֵינַיִם בְּאִשָּׁה יוֹתֵר מִגּוּפוֹ שֶׁל מַעֲשֶׂה, שֶׁנֶּאֱמַר: ״טוֹב מַרְאֵה עֵינַיִם מֵהֲלׇךְ נָפֶשׁ״.
Rav Yosef said: From here there is an allusion to the idea that blind people eat but are not fully satisfied when they eat because they cannot see their food. Seeing the food contributes to the enjoyment of eating. Abaye said: Therefore, from what we have just learned, one who has a meal should eat it only during daytime, when there is light to see the food that is being eaten. Rabbi Zeira said: What is the verse that alludes to this? “Better is the seeing of the eyes than the wandering of the desire” (Ecclesiastes 6:9). On the same verse, Reish Lakish said: The sight of a woman is better than the actual act of relations, as it is stated: “Better is the seeing of the eyes than the wandering of the desire.”

Mishneh Torah, Blessings

Rabbi Moshe ben Maimon, "Maimonides"