The report found that sales of low-calorie fast food rose by 432 percent compared with February, while the growth rate for low-sugar cereal products and low-sugar coffee and milk tea was 222 percent and 100 percent respectively.

Dong said low-sugar yogurt was in high demand in March, with sales of chia seed yogurt and probiotic yogurt, which aid digestion, rising month-on-month by 597 percent and 139 percent respectively.

She added that different age groups have contrasting preferences when buying healthy and functional foods. The post-1975 generation prefers dark chocolate; the post-1985 age group likes low-fat or skimmed milk and oolong tea; while the post-1995 generation prefers low-sugar coffee and milk tea.

"Male customers like to drink oolong tea and eat dietary fiber. Female consumers prefer low-calorie drinks and probiotics (microorganisms introduced into the body for their beneficial qualities)," Dong said, adding that running and yoga are the most popular sports for each gender.

Sales of nutritional products, including probiotics, proteins and enzymes, have risen significantly, along with those for products that help relieve fatigue.

In addition to rising search numbers among customers for healthy food, Dong said food companies have launched new products as a result of growing demand.

This trend is being seen online and offline. Alibaba-owned grocery retail chain Freshippo recently launched numerous low-fat, low-sugar and low-calorie products, including low-fat ham, low-fat milk and quinoa chicken sandwiches.

Yu Chaoqi, a purchasing head at Freshippo, said that in the past two months sales of low-fat, low-sugar and low-calorie food have risen significantly compared with previous years. With summer arriving, low-sugar drinks are in demand, with Chinese brand Genki Forest the most popular, he said.

"Zero-calorie granulated sugar chocolate products have sold well since they were put on the shelves, especially the ChocZero and Chocday brands," Yu said.

"Our clients are the new middle class who pursue high-quality lifestyles, and even though some products are labeled 'low sugar', they will check the nutrition information to verify this," Yu said.