The Consumer Council has found that more than 70 percent of cheeses it tested were high in fat, while more than 60 percent were high in salt.
The survey of 40 types of natural and processed cheeses also found that 45 percent were simultaneously high in fat and sodium.
Although 90 percent were high in calcium and protein, the watchdog warned consumers to eat them in moderation to avoid health risks such as obesity or high blood pressure resulting from long-term excessive intake of fat and sodium.
Of the natural cheeses tested, 28 are priced between HK$15 and HK$71 per 100 grams. They include cheddar, mozzarella and parmesan.
The other 12 brands were processed cheeses, with prices ranging from HK$12.50 to HK$45 per 100g.
The council found that the average sodium content of the processed cheese was double that found in natural brands, with the sodium content reaching 1,194mg per 100g of solid food sample.
One processed cheese - Anlene's "high calcium reduced fat processed cheese" - had the highest sodium content, at 1,660mg per 100g of cheese. Consuming one slice of the cheese means a sodium intake of around 345mg - 17 percent of the daily maximum recommended by the World Health Organization for an adult.
"Despite [Anlene's cheese] having a smaller portion size, consumers still need to keep their eating habits in check and avoid consuming too many slices at a time," said Nora Tam Fung-yee, the chairwoman of the council's research and testing committee.
Natural cheese had a higher average total fat content than processed cheese. One such product - "Etoki Reserve Le Fromage Basque Sheep's Milk Cheese" found in Citysuper - had the highest total fat content of 37.7g per 100g of cheese.
Pata Negra House Parmigiano Reggiano 14 months, a Parmesan cheese found in department store Yata, had the highest trans fat content, with 1.9g per 100 grams of cheese. If an adult consumed 26 grams of that Parmesan cheese, "they would have a trans fat intake amounting to 23 percent of the maximum daily intake limit recommended by WHO," Tam said.
Other than cheese, the council also tested 12 crayon and seven fingerpaint brands and found more than half of the children's art materials tested released toxic metal substances.
That includes a blue crayon from Caran d'Ache's Hobby Line 1/2 watersoluble wax pastel Hobby Line, which had the highest level of aluminum migration level at 33,000ppm, which exceeds the existing EU toy safety directive limit of 5,625 parts per million by almost five times.
The watchdog said that the acute toxicity of aluminum is relatively low, but excessive long-term intake could cause chronic diseases such as aluminosis, a lung disease.
"Besides selecting suitable children's art supplies with care, parents should also pay heed to the way their children use the materials and make sure they wash their hands thoroughly after use in order to reduce the risk of ingesting harmful substances," Tam said.
Seven out of the 12 crayons tested were found to contain a harmful substance called polycyclic aromatic hydrocarbon that exceeded the limit set by Germany.
Some of these hydrocarbon substances are allergens for the skin and respiratory tract and may cause rashes or allergic reactions from prolonged contact.