The Sugarpova Candy Lounge opened on Wimbledon High Street on June 16 and is selling treats to tennis fans during the prestigious championships.
Products include Sporty Mix tennis ball-shaped chewing gum.
Sharapova, 27, the world's wealthiest female athlete, founded the sweet firm in 2012 with her own money and considered temporarily changing her surname to Sugarpova during the US Open last year to promote the "premium candy line".
But the tennis star's sugary sales pitch coincides with the publication of a report which recommended that people should more than halve their intake of added sugar, The Independent reported.
A draft report by the UK's Scientific Advisory Committee on Nutrition said sugar should account for no more than five cent of a person's energy intake, despite many failing to meet the previous 10 per cent target.
Professor Tom Sanders, the head of diabetes and nutritional sciences at King's College London, said: "I find sporting celebrity endorsements of unhealthy foods such as sweets and soft drinks reprehensible. The use of player's clothing to promote cigarettes was outlawed almost 30 years ago – now it is time to crackdown on player endorsement of unhealthy foods.
Sanders said Sharapova's move bears comparison with Martina Navratilova's decision to wear clothes emblazoned with cigarette advertising in 1982.
"I would like to see an outright ban on sports personalities being involved in the advertising or marketing of sugar sweetened drinks, confectionary and crisps. Celebrity endorsement has a huge impact on sales to young people who are those most at risk of become obese," the paper quoted Sanders as saying.
Kawther Hashem, a nutritionist working with the campaign group Action on Sugar, agreed that celebrity endorsement sends the wrong message: "The underlying cause of obesity and diet- related illnesses is our food and drink environment. Sugary sweets should not be associated with Wimbledon, full stop."
Max Eisenbud, Sharapova's agent, denied children were targeted by the firm.
"If you look at the product, it's very premium. There's no aiming or targeted marketing towards kids.... It's pretty expensive. I don't think kids are coming to buy Sugarpova, I think they buy other types of candy. We're not targeting kids, we never have. Obviously kids are going to buy it, but we're not targeting kids."