So how did she? Holly herself has been reluctant to discuss weight loss in the past.
She has said: "It's a personal thing for me, and I think people get obsessive with it."
She added, during the Sunday Times interview: "Everybody knows what leads to a healthy lifestyle, but it's not up to me to give you a blow-by-blow account of what I've eaten that day. It's not helpful, and it's not what's important."
However, experts and insiders have given some insight.
Holly Willoughby weight loss: This Morning star's diet and exercise plan (Image: GETTY/INSTAGRAM/HOLLYWILLOUGHBY)
Holly Willoughby weight loss: Holly herself has been reluctant to discuss weight loss in the past (Image: INSTAGRAM/HOLLYWILLOUGHBY)