The "Britain's Got Talent" judge also says that a healthy lifestyle and a happy-go-lucky outlook make you attractive.
"Beauty comes from within. If you put your health before vanity, you will have an inner glow," femalefirst.co.uk quoted Dixon as saying.
The 34-year-old has now become Avon's beauty ambassador, a role which she hopes to use to promote charitable causes close to her heart.
"I love how much work they do to empower women, from the work they do with breast cancer and domestic violence to giving women independence through recruitment," she said.
Dixon also said that she doesn't do much to keep in shape.
"Whatever works for the individual person, but I personally don't diet, I believe in moderation - 90 percent of the time I'm very healthy, but if I fancy chocolate or crisps then I allow myself a treat and I don't feel guilty for it. I don't have any tricks. I enjoy exercising and I work out when I have the time," she said.
