1. Excessive fat intake has been linked to major health problems, including an increased risk of heart disease, obesity, hypertension, diabetes and certain types of cancers, while excess trans fat (TFA) and saturated fat (SFA) intakes have been linked to increase risk of coronary heart disease.  Furthermore, the World Health Organization (WHO) suggested that industrially produced TFA is not part of a healthy diet and should be avoided.

2. The Centre for Food Safety (CFS) and the Consumer Council (CC) has conducted another joint study, and tested the TFA content as well as estimated the industrially produced TFA content in foods commonly available in Hong Kong.  The objectives of the study are to a) serve for continuous monitoring the changes of TFAs level in foods, particularly those found to contain relatively higher levels of TFAs in previous studies; b) inform the public on the TFA content in food to enable informed choices; and c) encourage the trade to provide healthier food products with less TFAs, especially industrially produced TFA contents through recipe reformulation.

3. WHO recommended that the daily intake of total fat, SFA and TFA should be less than 30%, 10% and 1% of daily energy intake respectively.  For a 2000 kcal diet, one should have less than 66g of total fat, 22g of SFA, and 2.2g of TFA daily.  WHO also called on industry to commit and act to replace industrially produced TFA with healthier fats and oils.  To meet this target, WHO called on the fats, oils and food industry, including the food service industry, to commit to reformulate foods to eliminate industrially produced TFA, i.e. not exceeding 2 grams per 100 grams of total fat or oil in all foods, without replacement with SFA.

The Study

4. The study covered 75 samples (9 types) of non-prepackaged foods collected from different food premises (chain or individual), e.g. fast food/ takeaway shops, bakery shops, and restaurants between November and December 2018.  These samples were tested for the TFA, total fat and SFA contents by the Food Research Laboratory.  In addition, industrially produced TFA was estimated using the Denmark’s deduction method, i.e. excluding TFA from ruminant's meat/ milk.1

1 Substitution of trans fatty acids in foods on the Danish market (2009).


TFA content per 100g food

5. Among the nine food items (totally 75 samples), the three highest mean TFA content in 100g food in descending order were: (i) Puff pastry of the Cream soup with puff pastry (2.5g), (ii) Cookies (0.90g), and (iii) Chicken pie (0.65g).  The mean [range] TFA content (per 100g of food) of the nine food items are shown as below. 

Food item
Item no.

TFA Mean [Range]
(g/100g food)

1. 酥皮 Pastry 8 2.5 [0.75 – 3.4]
2. 忌廉湯 Cream soup 8 0.082 [0.0036 – 0.21]
3. 雞批 Chicken pie 9 0.65 [0.24 - 1.0]
4. 蛋撻 Egg tart 8 0.43 [0.12 – 0.97]
5. 咖哩角╱酥皮卷 Samosa/ Meat stuffed pastry roll 9 0.38 [0.14 – 0.77]
6. 曲奇 Cookies 6 0.90 [0.51 – 1.4]
7. 蛋糕 Cake 8 0.41 [0.076 – 1.1]
8. 中式╱甜酥餅Chinese/ Sweet pastry 8 0.32 [0.11 – 1.2]
9. 其他Others 11 0.25 [0.043 – 0.81]

Industrially produced TFA/total fat (%)

6. Among the nine food items, the three highest mean industrially produced TFA/fat (%) in descending order were: (i) Puff pastry of the Cream soup with puff pastry (8.9%), (ii) Chicken pie (2.7%), and (iii) Samosa/ Meat stuffed pastry roll (1.4%).  The mean [range] industrially produced TFA/fat (%) of the nine food items and the number of items exceeding 2% are shown as below.

Food item
Item no.
Industrially produced TFA/fat
Mean [Range]
No. of items Industrially produced TFA/fat exceeding 2%

1. 酥皮 Pastry


8.9% [0%-12%]


2. 忌廉湯 Cream soup


0.32% [0%-1.1%]


3. 雞批 Chicken pie


2.7% [0.87%-4.3%]


4. 蛋撻 Egg tart


1.1% [0.28%-2.0%]


5. 咖哩角╱酥皮卷 Samosa/ Meat stuffed pastry roll


1.4% [0%-2.7%]


6. 曲奇 Cookies


0.78% [0% - 2.5%]


7. 蛋糕 Cake


1.4% [0%-4.2%]


8. 中式╱甜酥餅Chinese/ Sweet pastry


0.80% [0%-1.3%]


9. 其他Others


1.0% [0%-2.5%]


Comparison of fatty acids profiles with the 2012 study

7. Of the 75 food samples covered in the current study, about 30 were also analysed in the 2012 study.  They covered all nine food items, each has one to seven counterpart samples.  The comparison of relevant results (mean [range]) is as follows:

  Current study 2012 study
Industrially produced TFA /Total fat (%) 2.0 [0-12] 1.5 [0-8.3]
TFA (g/100g food) 0.59 [0-3.0] 0.50 [0-2.5]
Total fat (g/100g food) 20 [2.5-29] 20 [1.9-32]
SFA (g/100g food) 7.6 [0.73-14] 7.4 [0.75-14]

8. In general, the fat content of similar foods varies greatly.  Compared with the 2012 study, the total fat content of foods remains similar.  However, there is no obvious downward trend on industrially produced TFA /total fat (%), SFA and TFA.  The results show that there is still room of improvement for the industry to further lower the industrially produced TFA levels in products.

Advice to the Public

Advice to the Trade

More Information

9. The related article is published in the CHOICE MAGAZINE (Issue 512, released on 17 June 2019) (Chinese only).

June 2019
Risk Assessment Section
Centre for Food Safety
Food and Environmental Hygiene Department