Tenzing Natural Energy

From £25.99 (pack of 24), tenzingnaturalenergy.com

Refreshing without being overly sweet, Tenzing’s range of natural sparkling energy drinks are available in four flavours, including Original, and Pineapple & Passionfruit (£35.99). With natural caffeine, vitamin C and electrolytes for an instant energy boost, they contain 48kcals per can, with no artificial sweeteners or additives. Each can also provides 80mg caffeine, 12mg vitamin C and 250mg electrolytes.