Sir David is joined by Simon Maxwell of the Overseas Development Institute, and by Francis Moore-Lappe of the Small Planet Institute.
Maxwell says governments have to respond by providing more social security, safety nets and famine relief.
Moore-Lappe says that hunger is not a result of a scarcity of food but a scarcity of democracy.
Also, Sir David is joined by American pollster Frank Luntz to discuss the presidential race.
Luntz says that despite Clinton's strong established support, Obama is the likely winner of the Democratic nomination; adding that if this happens a segment of Democratic voters are likely to vote for McCain.
A McCain and Obama election, Luntz says, is too close to call.
