The number of events at Diamond League meetings will reduce from 32 to 24 next year, officials from the IAAF announced yesterday.
In a year-long review, the international athletics governing body also decided each meeting will scale down from two hours to 90 minutes.
There will be just 12 Diamond League meetings as opposed to 14, and only one season final from 2020.
And the longest distance track race will be set at 3,000 metres.
“We can make the Diamond League even stronger and more relevant to the world our athletes and our fans live in today,” said IAAF president Lord Coe.
The new season, which starts on 3 May in Doha, will be the 10th edition of the competition.
Meanwhile, Britain’s Mo Farah has defended his title in the Big Half race, finishing in one hour one minute 14 seconds in London at the weekend.
The four-time Olympic champion won the half marathon in a sprint finish to beat his time of 1:01:40 in the inaugural event last year.
The 13.1-mile race is the 35-year-old’s final one before he goes for a first London Marathon win on 28 April.
In the women’s race, Britain’s in-form Charlotte Purdue retained her title.
The 27-year-old finished in a time of 1:10:38, with Steph Twell claiming second place ahead of Charlotte Arter.
“Conditions were a bit tougher than last year here – very windy, rainy – but it was nice. I got the job done, came first and now I’m preparing for the London Marathon and it’s a nice stepping stone,” Farah told the BBC.
“When I’m in London, the crowds always deliver. It’s a great atmosphere and I enjoy racing at home.
“Training has gone well [for the London Marathon]. Obviously I’ll have to have a chat with my coach and see how I feel.
“I’m excited. I feel like I have more experience than last year. I’ve got to go out and do the best I can – but I know I can mix in with the guys.”
Farah again hinted at a surprise return to the track to run the 10,000m at October’s World Championships in Doha.
“It’s possible. After the marathon, I’ll make a decision about what I want to do,” he added.
“Deep down, I miss the track. I look at my fellow athletes and I think, ‘Woah’ and I just get excited.”
Farah, who finished third at last year’s London Marathon, failed to reclaim the title of Europe’s fastest half marathon runner – a record he achieved by finishing the 2015 Great North Run in a personal best time of 59:22.
Switzerland’s Julien Wanders beat that record by finishing in 59:13 at the Ras Al Khaimah Half Marathon in February.
Elsewhere, David Weir won by a margin of over three minutes in the elite men’s wheelchair race, with a time of 51:11.
Fellow Briton Mel Nicholls came second in the elite women’s wheelchair event, narrowly finishing behind Margriet van den Broek of the Netherlands.