The Mental Health Foundation is asking for a 'please explain' from Uber Eats, after customers received a survey that probed not just product or delivery quality, but about customers' moods.

The survey questions included: "During the last month, how often have you felt happy?" and: "During the last month, how often have you felt not so good?"

"They're definitely questions about your state of emotions, your state of mind, and your wellbeing really, and very much might be the sort of questions someone might be asking you if they were trying to get a sense of your mental health," the Mental Health Foundation's Sean Robinson told Checkpoint.

"It's very perplexing. As someone who lives with bipolar disorder I want to encourage open conversations about mental health.

"For that to happen you have to trust the people you're talking to and you need to know why you're having that conversation. And for the life of me I can't figure out why Uber Eats wants to have that conversation with me.

"The only thing I can guess at is they want to use it to try use manipulative marketing to try sell me different types of food. If that's not the case I challenge Uber to come out and say why they're asking people these questions."

In a statement to Checkpoint, Uber Eats said: "This survey was developed to provide insights into the relationship between how people rate their experience on food delivery platforms and their general sentiment.

"We apologise that this intention was not made clearer and we are taking on this feedback."

But Mr Robinson said there is much for Uber Eats to explain.

"What are they doing with the information? This is quite personal information. How is being used? Is it being on-sold to other organisations? There are all kinds of ethical and privacy issues tied up in this."