To many people, new year means one thing: time to shed excess pounds. But will eating less really help? Experts say that the real problem lies in the quantity of sugar hidden in the food we eat. So is Britain addicted to sugar? Dispatches investigates how sugar affects the way our brains work; exposes how the food industry has rapidly increased the sugar in many of our favourite foods; and reveals how a powerful group of companies have tried to fight off any attempt to reduce the amount of sugar we all consume.