The findings, based on independent data from Nielsen, reveal a 1% growth to £6.08bn in sales in the take-home soft drinks sector last year, but poor summer weather and nervous consumer spending meant volumes fell 2%.
The strongest performance came from the energy drinks category, which recorded volume and value sales growth of 12% to £522m.
After energy drinks, sports drinks were the second-fastest growing sub-category with a 7% hike to £166m. Juice drinks, such as Ribena, Capri-Sun and Robinsons Fruit Shoot, held steady with value sales dipping 1% to £480m and volume up 1%.
Bottled water and smoothies suffered from higher price premiums and a wet summer, slumping 9% to £417m and 20% to £172m respectively.
Meanwhile, cola retained its position as the biggest sub-category, up 4% to £1.29bn.
This was down to one brand in particular, said Andrew Richards, customer management director at Britvic.
"With a 15% jump in sales, Pepsi Max drove a significant amount of growth in the cola category thanks to improved distribution in the impulse market and a strong marketing campaign."
Despite reduced consumer spending, the value tier of soft drinks slumped 6%. Consumers were increasingly choosing branded products over own label, added Richards.
"Branded sales have held up well in the onset of the economic downturn with consumers gravitating toward names they trust," he said. "Tertiary brands have found it harder to find a voice."
As for the rest of 2009, Richards expected innovation to be a key feature.
"Retailers are pleased manufacturers are not taking the foot off the pedal in terms of new product development, as they had been concerned we would batten down the hatches to focus on value."