Anne Milton said the the term fat was more likely to motivate people into losing weight, adding it was important people took ”personal responsibility” for their lifestyles.
Stressing she was speaking in a personal capacity, she told the BBC: ”If I look in the mirror and think I am obese I think I am less worried than if I think I am fat.”
Too many staff working in the NHS were worried about using the term, Ms Milton said, but suggested it could help encourage ”personal responsibility”.
She added: ”At the end of the day you cannot do it for them. People have to have the information.”
It comes as the National Institute for Health and Clinical Excellence (Nice) publishes guidelines on pregnancy, saying NHS staff are dealing with ”an epidemic of obesity” among pregnant women.
Also, the Government confirmed it is ditching plans for a review of the smoking ban, which could have seen it extended to pub doorways and beer gardens.
Ms Milton said there would be no review as promised by the previous Government following legislation in 2007.
The issue of whether the ban should be extended to beer gardens and pub doorways was expected to have formed part of the review.
”We are not rolling back the smoking ban, nor are we deploying austerity as an excuse for deregulation,” Ms Milton told health experts in central London.
”Instead, we have studied the smokefree legislation and decided not to proceed with the planned review because we feel the legislation is working.
”We will keep working on the evidence base for tobacco control, and will say more about our plans in the public health white paper.”
The Government is currently considering whether to reverse a ban – brought in under Labour – on cigarette vending machines and tobacco displays in shops.
A law was passed by MPs in October but the regulations needed to implement the changes have not come into force and may not be introduced by the current Government.
Health campaigners have reacted angrily, calling on the Government not to scrap the law.
They say children’s health must come before the needs of retailers, who have expressed worries about the financial impact.