How pack sizes are sabotaging your weight management... and what you can do about it

The pack size effect is something we have all been trapped by. It is that surprised feeling when your hand hits the bottom of a large bucket of popcorn, or that ‘sharing’ bag of crisps (which was meant to last tomorrow as well, but seems to be empty already). So many snacks are marketed in ‘sharing’ size packets, or packs that are meant to hold more than one portion. The trouble is, our brains really struggle with the idea of a packet containing more than one portion - to us, the portion is the packet. No matter how hard we try, eating anything less than the whole packet, is impossible. It is an impulse, and an example of how habits that are stored deeply in your memory can drive your eating.

Why does this happen?

One explanation for the "pack size effect" is that we subconsciously get information from packet sizes, and what we see is "this portion in this packet is ‘normal’, and what most people like me eat". We may not think this or say it outloud, but this is part of our brain's automatic response, and seeing this packet size as normal, and what other people might eat, gives us the impulse to eat the whole packet. It has also been suggested that the pack tells us the upper-limit, or maximum amount for a snack size, and we feel that one pack is ‘okay’ and not excessive. In short, bigger packets allow for more food to be eaten.

What you can do

1. Now you know about this effect, plan ahead. Set up your own kitchen, and food purchases so that you’ve got the best possible chance here. Try getting small individually wrapped chocolate bars instead of large family size blocks of chocolate. Opening a new small pack of chocolate is harder than beaking off another 4 squares from a pack that is already open. Get individual portions of popcorn or crisps, instead of a larger sharing bags. If a larger pack size is cheaper, then work out how you might be able to divide that up into portions once home. It will involve weighing scales and bags/boxes, so there is a bit of admin involved, if you want to save money. Not always are the larger packs cheaper however, so it is worth checking.

"Portion" of chocolate (four squares) and the equivalent as a Cadbury's Little bar.

2. One study found that having a reminder around about the reasons for losing weight means that people eat less from a pack. The study used traditional “diet cues”, like slimming magazines. We can go one better here, though. Traditional diet cues can be negative and even threatening at times, so they don't always get the best results. To really increase your motivation, you could use a positive reminder of why you are making a choice to eat less. If you have done some work on your values in 1:1 coaching with me, this can guide you, if not then pick something that is important to you.

One client kept a bottle of nice handcream on her desk to remind her of her commitment to self-care.

3. Having a picture of a serving size is more meaningful to us than simply noting how many grams is in a portion. If there is a snack that you prefer to buy in a larger pack, weigh out a portion for yourself one day, and take a picture of it. Use that as your guide. At Easter we are presented with chocolate repackaged in all sorts of unfamiliar shapes and sizes, including pack sizes that are bigger than usual. I’ve taken some pictures of a few of the typical Easter egg sizes and their equivalent in other presentations of chocolate.

One Cadburys 'large' Easter egg (156g) is the equivalent of 31 squares of chocolate.

Half of a 'large' Cadbury's Easter egg is the equivalent of four Cadbury's little bars.

Good luck training your brain to overcome this impulse! I hope these tools and strategies are helpful. Please feedback if you find this helpful, and what topics you'd be interested to hear about in future blogs. wendy@neverdiet.co.uk

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