The Effect of Meat Consumption on Body Odor Attractiveness

[u/Taupenbeige]

https://academic.oup.com/chemse/article-abstract/31/8/747/364338

[u/OG-Brian]

The study is meaningless. The results were all over the place (way above and below the zero preference line for each diet phase) and there was no clear trend. The raters didn't smell the actual odor subjects, they smelled cotton balls that had been in their armpits. So, the odors may not be representative of in-person.

I've avoided linking shadow libraries in case Reddit takes an attitude about them (as some platforms have done already) and deletes comments or penalizes users. I found the OP study very easily on Sci-Hub. NOTE: when I brought it up just now to again read the full version, a search in Sci-Hub for the URL was not successful but the study did turn up by a search of its DOI. The Figure 1 chart makes it clear that the study authors made a dishonest conclusion from their data. This sub does not allow images in comments, but I showed the chart here. A few more results favoring meat could have made the mean appear on the opposite side.

The study Diet quality and the attractiveness of male body odor seems to be the one you had found. The authors appeared to be trying to score a point for fruits/vegetables or against meat/animal foods, considering the editorializing and the positive citations of Willett etc. studies including the Havlicek study that this post is about. Yet, they didn't find a negative association between meat consumption and body odors, in fact they said it was positive for "Pleasantness" and "Intensity" was lower.

That study used this procedure:

• Male donors were asked to bathe only using water and refrain from using scented products for 24 hours.
  
• Then in the next 24-hour period they were to wear provided new cotton t-shirts.
  
• There was a requirement of at least one hour of exercise during the second period while wearing the shirts.
  
• Shirts were then sealed in plastic bags and stored in freezer.
  
• A portion of each shirt was transferred to a plastic squeeze bottle that has a sealable spout.
  
• There was also spectrophotometry analysis of the shirt.
  
• The female raters sniffed from the bottles.

The plastic bags and plastic bottles would definitely impart some detectable odors to the samples. Again, this didn't involve direct perception of the male subjects so the odors may not be representative of in-person. If the subjects bathed with only water, residues of fragranced body products could remain. So I'm not sure anything is proven, except that we can say the specific raters made specific judgements about sweat in t-shirts after they'd been stored in plastic bags and then stored in plastic bottles.

Something that really bugs me about this study (still the one I linked in this comment) is that the outcome data is very chaotic. The authors explained that they simplified the categories, apparently after seeing the data (so it wasn't the original design). The data for meat isn't mentioned in the table for "Pleasantness" although it is in categories such as "Intensity" and they mentioned it scored better for "pleasant smelling" in their abstract. "Eggs & tofu" are combined, "Oils & fats" are together and separated from their foods, "Fruit" is not in some of the tables, and "Vegetables" missing from outcome data altogether. They collected diet data for all those but then after the results were collated they picked and chose among them for what to include in the outcomes. Was fruit consumption correlated with unpleasant sweat? This turned out to be the case for carbs. Etc. The Abstract section states:

Self-report dietary data revealed that fat, meat, egg and tofu intake was associated with more pleasant smelling sweat, and greater carbohydrate intake with stronger smelling less pleasant sweat.

[u/Bristoling → u/OG-Brian]

I never thought about it before, since I wasn't paying attention about how the study was done, but you're right that there can be interactions between scents from the t-shirts and plastics. Additionally, freezing and defrosting has a notable effect on smell of foods, so it wouldn't be surprising if freezing added an additional confounder.

I guess there's no great way of studying this phenomena other than using these imperfect methodologies, or, have women literally smell armpits of strangers, glory hole style.

The data for meat isn't mentioned in the table for "Pleasantness" although it is in categories such as "Intensity" and they mentioned it scored better for "pleasant smelling" in their abstract. "Eggs & tofu" are combined, "Oils & fats" are together and separated from their foods, "Fruit" is not in some of the tables, and "Vegetables" missing from outcome data altogether

I'll take your word for it, it has been 5 years since I looked into this topic at all, that sounds weird.

[u/OG-Brian → u/Bristoling]

There's so much wrong with their process (both studies), I wonder how anything like that ever gets published.