Why's clotted cream yellow? Could squid and chips replace fish and chips as our national dish? And where do multivitamins come from?

Bergamot provides flavour in Jimmy's Earl Grey tea, but what exactly is it? How does instant tea match up against tea bags? Kate visits a very colourful jelly bean factory. Plus: pork scratchings.

How much prawn's in a prawn cracker? What's in low-salt food instead of salt? Plus: the new high-tech method for keeping fresh herbs alive for longer. And a basil plant that's half tree.

Kate meets a scientist who hopes his genetically engineered goats' milk could save 500,000 lives a year. Is the fish we're buying really what we think it is? And what exactly is spreadable butter?

In this Food Unwrapped diet special, Jimmy Doherty, Kate Quilton, Matt Tebbutt and guest presenter Kiran Jethwa cross the globe to unearth the very latest dietary trends and scientific advances in the world of weight loss. In Los Angeles, home of the body beautiful, Kate investigates reports that caffeine could be a powerful secret weapon in the battle of the bulge. Could a double espresso really help us burn extra calories, even after we finish exercising? Kate meets one of California's leading sports scientists to find out. Jimmy visits Belgium on the trail of the dieter's holy grail: a chocolate that could be good for you. The secret? It's a probiotic chocolate bar, packed with bacteria that are supposed to keep us healthy and even help us stay slim. But how does probiotic chocolate stack up against other gut-friendly foods such as sauerkraut or yoghurt?

Can high-tech surveillance save our salmon? How on earth can you barbecue a kangaroo? Plus: the secrets behind the annual race to get seasonal asparagus into supermarkets.