What is the difference between 保たせようと and 保とうと in this sentence?


そして料理が来るまでの間、どうにか腹を **保たせようと** 、店員がテーブルに置いていった水を一気に飲み干した。

Hi. What is the difference between 保たせようと and 保とうと in this sentence? Isn’t 保つ
an transitive verb so we don’t need to change it into causative form?

Thank you.




Firstly, [保つ](https://dictionary.goo.ne.jp/word/%E4%BF%9D%E3%81%A4/) actually
has intransitive meaning "to sustain".

> **３** その状態が変わらないで長く続く。もつ。「からだが―・たない」「寿命が―・つ」

However, what way more important here is that, I suspect, it should be read
**もつ** rather than **たもつ** in this context so that it makes sense, because we
have an idiom 腹がもつ "one's stomach holds up" or "be in the state of satiety for
a while". What the speaker does is to _make_ their "stomach holds up" or to
stay their hunger, thus should use the causative 腹をもたせる.

Although the majority of people spell the phrase with the kanji 持つ (腹が持つ,
腹持ち), as it is technically the only way taught in the school, 保つ
([腹が保つ](https://www.google.com/search?q=%22%E8%85%B9%E3%81%8C%E4%BF%9D%E3%81%A4%22),
[腹保ち](https://www.google.com/search?q=%22%E8%85%B9%E4%BF%9D%E3%81%A1%22)) also
has a steady number in the search result.




Firstly, [保つ](https://dictionary.goo.ne.jp/word/%E4%BF%9D%E3%81%A4/) actually
has intransitive meaning "to sustain".

> **３** その状態が変わらないで長く続く。もつ。「からだが―・たない」「寿命が―・つ」

However, what way more important here is that, I suspect, it should be read
**もつ** rather than **たもつ** in this context so that it makes sense, because we
have an idiom 腹がもつ "one's stomach holds up" or "be in the state of satiety for
a while". What the speaker does is to _make_ their "stomach holds up" or to
stay their hunger, thus should use the causative 腹をもたせる.

Although the majority of people spell the phrase with the kanji 持つ (腹が持つ,
腹持ち), as it is technically the only way taught in the school, 保つ
([腹が保つ](https://www.google.com/search?q=%22%E8%85%B9%E3%81%8C%E4%BF%9D%E3%81%A4%22),
[腹保ち](https://www.google.com/search?q=%22%E8%85%B9%E4%BF%9D%E3%81%A1%22)) also
has a steady number in the search result.

