Helen Skelton got "scared" after she suffered a reaction to diet pills.
The 34-year-old TV presenter appeared on 'Lorraine' on Wednesday (03.01.18) to promote her new ITV2 show 'Exercise: New Year, New Year?', which examines fad diets and alternative exercise regimes, but she admitted she was really "surprised and scared" after popping some tablets to help her lose weight.
Speaking to Lorraine Kelly, Helen said: "When I tried the fat-burning pills, I thought 'I'm tough as nails, these won't affect me'.
"We did an experiment with fat burning pills and I tried them in a controlled environment and I was really surprised and scared at the results.
"I thought I'd know how my body would react but I felt absolutely awful. It was scary.
"I couldn't really concentrate, I was all over the place, my heart was racing and I was a bit embarrassed to admit that, I thought it wouldn't affect me but it did.
"We have to be very, very careful because in this day and age people want a quick fix.
"The amount of people now who take fat burning pills and slimming pills is really scary and for some people that can lead on to some very serious issues and problems."
Helen - who became a household name as a presenter on 'Blue Peter' - also spoke about trying different fitness trends like pole dancing to show what various exercises people do to get fit after the Christmas period.
Her new two-part special also looks at the cost on the NHS if people don't exercise and the "quick-fixes" society will pay in order to lose weight fast.
Last year, the TV star welcomed her son Louis into the world while she was sat on the kitchen floor of her family home in Perpignan, France, on April 8.