Representatives from the food industry, NGOs, academia and government met in London today (21 May) to discuss one of the most complex issues - how to alleviate the sector's impact on the environment. Held in the run-up to the UN's Rio +20 event next month, delegates and speakers debated how all stakeholders could make the sector more sustainable. Here, in a series of soundbites, is a flavour of what they had to say.

"We need Rio to trigger a profound shift in the way both business and government think about growth. It's important that the private sector makes its voice heard to show this is an economic issue as much as this is an environmental or development issue" - UK Secretary of State for Environment, Food and Rural Affairs Caroline Spelman.

"We haven't really got a clue in academic terms what sustainable means when it comes to producing food and agricultural systems, simply because of the indirect impacts they have" - Professor Tim Benton, Institute of Integrative and Comparative Biology, University of Leeds.

"There has been phenomenal change already but we also have to be honest and say there is much that has yet to change. There is yet still so far to really pull the food and drink industry to really embracing fair and green growth" - Harriet Lamb, executive director at The Fairtrade Foundation.

"The engagement of business is absolutely paramount when dealing with sustainability agenda" - Spelman.

"Clearly we as an industry have a responsibility to source sustainability and drive change but we can't do that in isolation. We need the frameworks within which to do that, not just at national level, we've got to remain competitive in world markets. There's got to be a level playing field. It does require political leadership, not just nationally but internationally" - Andrew Kuyk, director of sustainability and competitiveness at the Food and Drink Federation.

"The food system is not sustainable and nor is it on course to be sustainable any time soon" - Dr Sally Uren, deputy chief executive, Forum for the Future.

"The roundtables on soy and palm oil are industry-developed standards that are pushing the limits of trying to develop a common platform for sustainability. We need those standards to be entrenched and adopted far more widely [and that] is something Rio is ideally placed to work on" - David Norman, director of campaigns at the WWF.

"Small-holders can be part of the big solution to finding fair, green growth that does put equity at its heart. If you start with the small holder and work up, you will find more sustainable solutions for tackling poverty and the environmental challenges" - Lamb.

"Over-consumption is form of food waste. It's not just about sustainable sourcing, it's about sustainable use" - Professor Benton.

"The Western diet is becoming aspirational throughout much of the world. London 2012 is sponsored by Coca-Cola and McDonald's ... but we don't have a sustainable diet sponsorship. Getting people to make the right food choices is as an important part of sustainable development as the developing world" - Professor Benton.

"No policy maker wants to be telling people what to do but the key is to get away from the sense that this is about voluntary behaviour. It's about getting the true cost of food into food" - Norman.

"We need to reconnect with the food that the eat. I would like to see brands and retailers much more actively engaging their consumers with how and where they favourite product is made" - Dr Uren.

"I want Rio to deliver a short, sharp, clear political declaration and food must be one of the central issues within that. I want to see recognition at Rio of the need to take action to tackle the scale of the challenge" - Spelman.