In view of growing evidence on the adverse health effects of trans fats intake and increasing concern of its presence in food, the Centre for Food Safety (CFS) and the Consumer Council (CC) have conducted joint studies on Trans Fats in Locally Available Foods Part 1 and Part 2. These studies aimed to assess trans fats levels in foods available in local market and enhance consumer understanding of trans fats and their health implications. In the Part 1 study, trans fats level in bakery products, deep fried foods and butter and margarine/ margarine-like spreads were the major focus. For this Part 2 study, trans fats levels in wider ranges of food products were covered.
2. Trans fats (also called trans fatty acids) are formed during a process called hydrogenation, which turns oil from liquid into semi-solid or solid form. Hydrogenated vegetable oils are used in food production for extending shelf-life and improving food texture and mouth-feel.
3. Trans fats are mostly found in hydrogenated vegetable oils such as shortenings and margarines. One of our main dietary sources of trans fats intake is from food produced with hydrogenated vegetable oil. Besides, we may also intake trans fats from natural sources e.g. small amount of trans fats are naturally present in milk and fat of cow and sheep.
4. There is increasing evidence showing the link between trans fats intake and coronary heart disease. Some studies indicate trans fats may even do more harm than saturated fats. Trans fats and saturated fats both raise low-density lipoprotein (LDL) cholesterol (so-called bad cholesterol) level. However, trans fats may also lower high-density lipoprotein (HDL) cholesterol (so-called good cholesterol) level.
5. The World Health Organization and the Food and Agriculture Organization of the United Nations suggest that diets should provide a very low level of trans fats, i.e. an intake of less than 1% of daily energy intake. For example, an individual with a daily energy intake of 2000 kilocalories should limit the intake of trans fats to less than 2.2 grams per day.
6. In Hong Kong, in response to public health concerns, trans fats has been included as one of the core nutrients in the Food and Drugs (Composition and Labelling) (Amendment: Requirements for Nutrition Labelling and Nutrition Claim) Regulation 2008 which was tabled at Legislative Council for discussion early this April. To facilitate consumers to make healthy food choices, all prepackaged foods applicable to the Regulation shall declare the trans fats content on label. In future, "Trans fats free" claim will also be permitted if the following condition is satisfied: (1) not more than 0.3 grams trans fats per 100 grams or millilitres of food; (2) not more than 1.5 grams saturated and trans fats per 100 grams of food or not more than 0.75 grams saturated and trans fats per 100 millilitres of food; and (3) not more than 10% energy from saturated and trans fats.
7. This Part 2 study covered various food products available in local market, including (i) bakery wares (e.g. cookies, wafers, crackers, pastries, doughnuts and French toasts etc.); (ii) ready-to-eat savouries (e.g. potato chips, tortillas and rice crackers etc.); (iii) instant noodles and its individually packed seasonings; (iv) soups; (v) milk products and analogues; (vi) mayonnaises; (vii) chocolate spreads; (viii) peanut butters; and (ix) chocolate.
8. A total of 85 food products, including both prepackaged and non-prepackaged products, were purchased from local market. Ninety (5 of them were individually packed seasonings in instant noodles) samples were subject to laboratory analyses including trans fats, saturated fats, total fat, cholesterol, and energy conducted by the Food Research Laboratory of CFS.
9. In this study, trans fats levels varied a lot among same kind of food. Such results indicated that it is practically possible to reduce trans fats levels in food. A summary of results is listed in the following table:
|Food products||No. of samples||Trans fats range (g/100g)|
|Bakery ware (e.g. cookies, wafers, crackers, pastries, doughnuts and French toasts etc.)||36||0.025-4.7|
|Ready-to-eat savoury (e.g. potato chips, tortillas and rice crackers etc.)||16||0-0.26|
|Instant noodle and its individually packed seasoning||7 noodles||0-0.24|
|5 packed seasonings|
|Milk product and analogue||6||0-0.32|
10. Some of the tested products were found to have a relatively high trans fats level. For example, a doughnut (47 grams) and a Chinese pastry (76 grams) sample contained about 4.7 and 1.7 grams of trans fats per 100 grams respectively. Consumption of one piece already comprises a significant percentage of the daily recommended intake limit i.e. 100% and 59% of an individual with a daily energy intake of 2000 kilocalories respectively.
11. Apart from trans fats, saturated fats and cholesterol are also risk factors for cardiovascular disease. Some non-dairy creamers and instant noodles were found to have relatively high amount of saturated fats, whereas French toast samples were found to contain relatively high cholesterol content.
12. The public is advised to maintain a balanced diet, choose foods that have lower trans fats, saturated fats and cholesterol content and avoid using hydrogenated oil/fat and animal fat in preparing food. Members of the public are also advised to make reference to the information in the Nutrition Label to make healthier food choices.
3. The trade is advised to avoid using hydrogenated oil/fat in preparing food and to provide healthier food choices to consumers. Information including nutrient contents and claims on label should not be misleading. The trade is advised to reduce trans fats and saturated fats in foods. Trade Guidelines on Reducing Trans Fats in Food is now available for trade reference.
Risk Assessment Section
Centre for Food Safety
Food and Environmental Hygiene Department
For the study report (only available in Chinese), please click the following website: