Body odor can be greatly affected by the foods you eat:<p><a href="https://www.allure.com/story/diet-body-odor-causes" rel="nofollow">https://www.allure.com/story/diet-body-odor-causes</a><p><a href="https://nutritionfacts.org/2014/08/19/how-eggs-can-impact-body-odor/" rel="nofollow">https://nutritionfacts.org/2014/08/19/how-eggs-can-impact-bo...</a><p>I learned about the effect of eggs when I tried a high protein, low carb diet where I ate 2 fried or scrambled eggs every morning. Within 3 days of starting the diet I developed an unpleasant fishy body odor, especially in my armpits. Normally I would eat 2 eggs once a week, at which level I did not develop the fishy smell. Even washing my armpits with soap did not eliminate the odor. I stopped eating eggs daily and within a couple of days the odor cleared again.<p>Similarly, I do a 10-12 day self supported pack hike most years. For lunch on these hikes I typically eat some form of processed meat (cacciatore sausage, salami etc) with processed cheese and dry biscuits. On these hikes I can usually swim or bathe in fresh water a few times each day without using any soap. I notice a slow increase in body odor, again mostly from my armpits over the course of the hike. I suspect the body odor may be caused by the garlic from the sausage. The other foods I eat are things I eat regularly without issue. Unlike with the eggs, this odor goes away with the first hot, soapy shower when I get back to civilisation.<p>Note that in the past I have had girlfriends comment that I had very low body odor compared to other guys they had dated.<p>So I suspect that successfully switching to a no or very low soap hygiene routine might be challenging for people whose diet and genetics mean they excrete odorous, non-water soluble compounds.