NO! This is terrible science reporting! The study doesn't say it MAKES you sad, the report said it's ASSOCIATED with being sad. There was NO causation in this study. It could just as easily be that sadness leads to eating processed food, which seems at least as likely as the other way around. And it could equally as likely be that some 3rd factor is what's causing both the junk food eating and the sadness.
OP if you care at all about being honest and not spreading misinformation then you should delete your blog post and this lemmy post.