The Skinny on Trans Fats

Here’s what you need to know about the ‘super villain’ of fats.

By Melody Foo, Dietitian, Ng Teng Fong General Hospital

Fat plays an important role as a source of energy, cushioning of vital organs, and as a transport system for fat soluble vitamins. However, fat should make up no more than 30-35% of our total energy intake.

According to the 2018 National Nutrition Survey (NNS), there has been a rise in Singaporeans’ fat intake from 28% in 2004 to 35% in 2018. This is a cause for concern, as fat is calorie dense, and any increase in fat intake may result in weight gain and obesity.

Types of Fat

There are four types of fat in our diet: polyunsaturated fat, monounsaturated fat, saturated fat and trans fat. The table below explains the differences in the 4 types of fat.

Types of Fats	Health Implications	Remarks
Polyunsaturated fat (PUFA)	Omega 3 fat helps to: Decrease blood clotting Reduce blood vessel hardening Lower blood triglyceride level (triglyceride is a type of fat found in the blood) Omega 6 fat helps to: Lower total and LDL-cholesterol*	Both PUFA and MUFA are unsaturated fat. Despite the health benefits of unsaturated fat, they should be consumed in moderation to prevent unnecessary weight gain.
Monounsaturated fat (MUFA)	Helps to lower total and LDL-cholesterol*
Saturated fat	Increases total and LDL-cholesterol*	Saturated fat intake should contribute to less than 10% of your total energy intake.
Trans Fat	Increases LDL-cholesterol* Decreases HDL-cholesterol+	Trans fat intake should be less than 2g/day, as per the World Health Organisation (WHO) guideline.

*Low-density lipoprotein (LDL)-cholesterol is commonly known as the “bad cholesterol”. LDL-cholesterol gets deposited in the walls of blood vessels resulting in blockages, increasing your risk of heart attack and stroke.+High-density lipoprotein (HDL)-cholesterol is commonly known as the “good cholesterol”. HDL-cholesterol helps to mop up cholesterol from the bloodstream and transport it back to the liver, subsequently reducing the amount of cholesterol deposited in the walls of blood vessels.

Among the four types of fat, trans fat is perhaps the fat less talked about. A high consumption of trans fat is worrying. Not only does it increase your LDL-cholesterol, it also decreases your HDL-cholesterol. Given the dangers of trans fat, it is therefore important to look at how to limit your intake of trans fat.

Trans Fat Explained

Trans fat is formed when unsaturated fat undergoes hydrogenation. There are two sources of trans fat: naturally-occurring and artificial trans fat. Naturally-occurring trans fat can be found in some meat and dairy. However, only small amounts are present. The primary and more significant source of trans fat in our diet is artificial trans fat; found in foods such as hard margarine, solid shortening, commercial deep-fried foods as well as baked goods. Food companies like to use trans fat, as it is inexpensive, easy to use, stable at high heat and gives food a longer shelf life.

Healthier Alternatives

Trans Fat Increases LDL Decreases HDL	Sources	Healthier Alternatives/Recommendations
Trans Fat Increases LDL Decreases HDL	Solid shortening, stick/hard margarine Foods containing (partially) hydrogenated vegetable oil and shortening: most puffs, pies, pastries, commercial deep-fried foods (e.g. nuggets, french fries)	Soft margarine Limit intake of foods containing vegetable shortening, hydrogenated or partially hydrogenated vegetable oil to no more than two times a week Look at the ingredients list. Trans fat can be termed as (partially) hydrogenated vegetable oil or shortening Choose foods with the Healthier Choice Symbol (HCS) which states trans fat free. Foods with this HCS logo contain less than 0.5g trans fat per 100g