AITA for telling my brother he smells foul and for banning him from my flat after he blamed his low carb diet and said it isn’t that bad?

Sometimes the most uncomfortable conversations happen with the people closest to us. And for one social media user, the issue wasn’t money, relationships, or family drama — it was something far more awkward: a terrible smell.

The woman explained that her brother recently developed an extremely strong odor that made it almost impossible for people to be around him. His breath, body odor, and even the smell he left behind after using the bathroom became so intense that she began avoiding being in the same space as him. When she finally decided to speak up and tell him directly, hoping to help him deal with the issue, the conversation quickly went sideways. Instead of appreciating the honesty, her brother insisted she was exaggerating — and even accused her of turning everyone against him.

‘AITA for telling my brother he smells foul and for banning him from my flat after he blamed his low carb diet and said it isn’t that bad?’

It all started when the woman began noticing a sudden and unusual change in her brother’s smell:

Over time, the situation became so bad that people struggled to be near him:

Knowing that people often can’t smell themselves, she decided to bring it up gently:

Conversations about body odor can be incredibly uncomfortable, even among close family members. Many people hesitate to bring it up because they’re worried about hurting someone’s feelings. Still, when the issue begins affecting daily interactions, staying silent may actually make things worse. In this case, the sister approached the topic directly but respectfully, hoping her brother would take it as helpful feedback rather than criticism.

The brother’s explanation adds an interesting twist. He believes the smell is caused by his new low-carb diet. Certain diets, particularly ketogenic diets, can produce something commonly known as “keto breath.” According to nutrition expert Kristin Kirkpatrick of the Cleveland Clinic, when the body burns fat for fuel it produces compounds called ketones. One of those compounds can create a breath odor similar to acetone or fermented fruit.

However, that phenomenon usually affects breath more than anything else. When body odor, urine, and other smells change drastically at the same time, it may signal something more complex. Sudden shifts in body odor can sometimes relate to medical issues, metabolic changes, or extreme dietary adjustments. That’s why many people in the discussion suggested the brother should consider seeing a doctor to rule out underlying health concerns.

Another factor at play is the emotional reaction to criticism. Even well-intentioned feedback can feel embarrassing or threatening. When people feel exposed or judged, they sometimes respond defensively rather than addressing the issue itself. Approaching the situation calmly, focusing on health rather than blame, and encouraging medical advice could help reduce tension while still addressing the problem.

Here’s what Redditors had to say:

Many people online felt the sister did the right thing by being honest.

Others focused on the possibility that something more serious might be happening:

Some commenters pointed out that honest feedback from loved ones can be valuable:

Honest conversations about personal issues can be uncomfortable, especially when they involve something as sensitive as body odor. In this case, the sister believed she was simply trying to help her brother become aware of a problem that might be affecting both his health and the people around him.

Her brother, however, saw it very differently and felt attacked instead. Situations like this raise an interesting question: is it better to be brutally honest with someone you care about, or should certain things be left unsaid?