The Duchess of Cambridge's Commonwealth events with the duke will be her last official engagements before starting her maternity leave, Kensington Palace has said.
William and Kate are due to show off their culinary skills and general knowledge later when they take part in a Commonwealth quiz and lunch to celebrate the family of nations.
A Kensington Palace spokeswoman said: "Today's public engagements by the Duke and Duchess of Cambridge will be Her Royal Highness's last before starting her maternity leave."
Despite being heavily pregnant with her third child, which is due in April, the duchess's schedule has been busy over the past few weeks.
Highlights have included attending her first official event with Meghan Markle, when the pair joined William and Prince Harry for a question and answer session about the royal trio's Royal Foundation and their charitable aims for the future.
And on Wednesday Kate launched a major project, an early years steering group, which will look at ways of improving how society supports children so they have the resilience to cope with life's pressures when adults.
The duchess's due date has not been released but it is thought the Cambridges' baby is expected a few days after the Queen's birthday, April 21.
If the latest addition to William and Kate's family arrives on time it is likely the duchess will be able to attend Harry and Ms Markle's wedding on May 19.
The duke and duchess will begin their day at the Olympic Park's Copper Box arena in Stratford, east London, for an event staged by SportsAid, a national charity helping the next generation of Olympic, Paralympic and Commonwealth champions.
The duke and duchess will take part in a Commonwealth quiz alongside athletes, coaches and supporters who will be questioned about their knowledge of the Commonwealth.
The couple will also watch a wheelchair basketball session and meet the players, some of whom hope to compete in the 2022 Commonwealth Games in Birmingham, and be shown a media training session for young athletes.
Every year SportsAid supports more than 1,000 athletes - the vast majority aged 12-18 - by providing a financial award to help with training and competition costs.
The charity also helps develop other vital skills for professional athletes by providing media training, nutritional advice and performance lifestyle guidance.
Later, at St Luke's Community Centre near Clerkenwell, William and Kate will help locals and volunteers put the finishing touches to a meal that is being prepared for this year's Commonwealth Big Lunch.
The Big Lunch project aims to encourage as many people as possible to sit down to a meal with members of their community once a year.
Commonwealth Big Lunches are part of the official celebrations leading up to the Commonwealth Heads of Government Meeting (CHOGM) being staged in London and Windsor Castle next month.
In the centre's cafe, William and Kate will be given a briefing on the work of St Luke's, which provides services and activities, has a range of facilities including a fully equipped cookery school and runs community classes on healthy home cooking and avoiding food waste.
The couple will also take part in a recipe workshop and discussion in the kitchen with locals, who regularly chat about their favourite dishes and what inspires them to make them.