Fat functionality: Why can't we just swap bad fats for good ones?

With huge consumer and political pressure to reduce levels of 'bad fats', and soaring demand for healthier foods containing 'good fats' like omega-3's, FoodNavigator asks why we can't simply switch the two.

At first glance it may seem like a very sensible idea. Simply take out the bad fats, and put in some good fat. After all, fat is fat, right? Wrong.

As many within the industry already know, finding a way to take out bad fats while keeping food looking and tasting the same is a big challenge. And adding in a healthy fat doesn't always make that challenge any easier, according to Els de Hoog of NIZO Food Research in the Netherlands.

Speaking with FoodNavigator, de Hoog explained that in almost every case, simply exchanging one 'bad' fat for different 'good' fat is impossible because of the different functionalities and behaviours that fats have.

"If you want to swap a bad fat for a good fat, basically the bad fats like saturated and trans fats are very hard. And the good ones, the unsaturated ones, they are soft or liquid at room temperature."

"This means that you will lose your structural functionality of the hard fat," she explained.

Indeed, de Hoog noted that fats play a wide variety of important functions within a food product, and that because of this you cannot simply swap out a fat.

"For fat in general, whether you want to replace a healthy for unhealthy, or just reduce fat - in all cases  you have to consider the functionality of fat, and that is difficult because it has multiple functions in the food at the same time."

The NIZO expert explained that fat plays a role in many aspects of our food - from building texture and structure, to adding flavour, adding lubrication, and having nutritional value in terms of both calories and the other nutrients that may be soluble in fat.

Any time a company looks to reduce or replace fats, they must consider this, said de Hoog

One example of this, she said, is ice cream - where fat forms crystals that make a 3D network which is important in the structure of ice cream, but also stabilises air that is trapped in the ice cream.

"If you take out that fat then you have to restore both the stabilising of the air pockets but also the three dimensional network," said de Hoog. "You can imagine that even if you took out the fat and replaced it with a softer fat that this network would not be possible."

The right solutions

Finding solutions that allow the switch out of harder, less healthy fats, for their softer - yet healthier - counterparts can be quite a challenge, however de Hoog noted that there are several solutions that can keep, or restore, the functionality of one fat while using another.