Senior judges at the Court of Appeal rejected Colin Gregg's bid to have all his convictions overturned but they agreed his sentence was "too long" and reduced it to eight-and-a-half years.
The 76-year-old, of Home Steadings, Gosforth, Newcastle was found guilty of nine counts of indecent assault against four boys - aged between 11 and 14 from the early 1960s to the 1990's in March.
One victim was abused in a swimming pool and others in a gym and sauna at his home.
Gregg watched the proceedings over a video link from prison.
Lord Justice Davis, sitting with Mrs Justice Nicola Davies and Judge Nicholas Dean QC, said the appeal against sentence must be allowed.