This time, gym buddies Lucy and Sue want to get bikini ready for a spa day in two weeks. Best friends Fi and Sarah shape up for Sarah's birthday party. And part time actors Bharat and Atul purge the pounds for a Bollywood film dance routine. The diets tested this time are the carb lovers diet; the low carb diet; the wild diet; the blood sugar diet; and the highly-regarded dash diet. Xand also road tests the latest diet gadgets and finds out if our gut microbiome may hold the key to weight loss.