Our ability to taste fat plays a key role in our appetite control. Natalie Filatoff investigates ways to stop your taste buds from weighing in.
If avoiding fatty foods is a constant struggle, don’t fret, it’s probably not entirely your fault. Scientists have found that there are a number of reasons why fat has such a hold over us.
Take evolution for starters. The presence of fat in your mouth tells your brain you have a kilojoule-rich food going down, and that you’d better stock up, because you never know when this big steak (or five-litre tub of ice-cream or family-sized packet of chips) will come your way again. In modern times, when food is plentiful, this instinctive drive to consume fat while it’s available plays a part in the way we gain weight, but it’s not the whole picture.
Feed the need
We reach for fat for various reasons. You may have become conditioned to eat fatty foods by your family’s habits, or by those of your social group. But when one bad habit becomes entrenched as an automatic response, your fat consumption can spiral out of control.
It’s called comfort food for a reason: fatty foods soothe our senses. But an awareness of why it’s so comforting can help us develop a healthier way to include fat in our diets.
Love the taste
Welcome to the palate pleasure dome, where fat equals fun. Our mouths are designed to love the feel of oil, cream, butter – in short, fat – says Damian Frank, a sensory flavour research scientist at the CSIRO.
He adds that, when you cook, the heat drives out the food’s moisture, helping flavours to concentrate in the fat. And when that fat breaks down in your mouth, it gradually coats your tongue, releasing those wonderful lip-smacking flavours. Conversely, if food is fat free, its flavours won’t last as long in your mouth.
Fat also enhances the textural variety of foods, making potato chips crisp and giving chocolate its satisfying solidity. “We love the sensation of food changing from one pleasant consistency to another in our mouth,” says Frank. When chips seem to dissolve on your tongue, or chocolate melts in your mouth, it’s a gratifying sensory, often sensual, experience.
Fat and happy
Research shows that eating fatty foods counteracts the stress response. Professor Margaret Morris, a psychopharmacologist at the University of New South Wales, has found that fat- and sugar-rich foods lower feelings of stress in animals, perhaps because eating such foods stimulates the brain to release feel-good hormones dopamine and serotonin. And these hormones positively influence mood in people, just as they do in animals.
It’s important to recognise that we need certain fats in our diet. Our cells require long- and short-chain fatty acids (the components of fat when the body breaks it down) to maintain cell walls, among other cellular processes. To this end, the body best absorbs many vitamins when they’re dissolved in fat. The betacarotene in tomatoes, for example, is more able to have an active effect on the body when tomatoes are cooked in a little olive oil.
In short, we’re naturally predisposed to seek some fat in our meals, so if we don’t get it, this inclination may contribute to our feeling unsatisfied and wanting to eat more or to eat and snack more often to feel full.
How sweet it is
In 2005, a Swedish study found that fat- and sugar-laden foods override our normal appetite regulation. In fact, these super-sweet and fatty foods are so attractive to us, they not only ramp up our hunger signals but also increase the amount we need to eat to feel satisfied.
On top of that, the dopamine release that makes us feel good may also drive us to return to fatty, sugary foods again and again.
Makes good sense
Some people are more sensitive to the taste of fat than others, according to new research from the Food Sensory Science Department at Victoria’s Deakin University.
As Associate Professor Russell Keast, who heads the department, explains, “If you’re less sensitive to fatty acids, you don’t feel full when you eat fat, so you’re likely to eat more of it, or more of something else, to satisfy your hunger.”
So, when people who are not sensitive to fat start eating a slice of bacon or a doughnut, for example, they’re likely to keep eating, because their body doesn’t tell them to stop. And these people are more likely to be overweight, as Keast’s research confirms that the taste buds of overweight and obese people are less sensitive to fat in foods.
Attack the fat
Here’s the important thing: Keast’s research also indicates that eating less fat actually increases your sensitivity to it. And with increased sensitivity comes better self-control.
His team placed people who were insensitive to fat, and who had become overweight or obese, on a low-fat diet for four weeks. He found they developed a significantly increased ability to identify low concentrations of fat.
This suggests that, over time, you can train yourself to find that you’ve satisfied with eating less fatty foods. And this is good news for those of us who feel powerless in the face of a tray of Tim Tams!
Five ways fat leads us to eat too much
Manufacturers formulate foods that are finely calibrated to give you maximum pleasure. So, while they gain repeat business, you gain weight. Here are five simple tactics that can help you control your fat intake.
1. Fat + salt is twice as tempting
If fat is a flavour vehicle, then salt is a flavour enhancer – this dynamic duo packs a double-whammy. Both salt and fat have ‘desensitising’ effects. The more you eat, the more you become dulled to the flavours, and the more you need to get that pleasing taste.
So, by eating these foods regularly, you can easily end up on a treadmill of heart-risky, salty, fat-laden and very high kilojoule foods.
Kick the cycle by making your own meals. This way, you can control how much fat and salt you add when you’re cooking.
2. Fat + sugar = soothing!
As Professor Margaret Morris observed, when you combine fat with sugar, it reduces stress. In fact, fatty and sugary foods are so attractive to us that they increase our hunger signals, while at the same time, raising the amount we need to eat to feel satisfied.
Fight those signals with foods that really do satisfy: lean meat, eggs, fish, chicken and nuts are all healthy protein sources which can boost satiety. And pile your plate with vegies as these take longer to chew, bulk up your meal and fill your tummy.
3. Fat is easy to eat
Foods that are soft and easy to swallow, like cakes, pastries and hot chips, hardly need chewing. You’ve wolfed down twice the volume as you would with a home-cooked meal or snack before you notice how bloated you now feel.
In contrast, chewy foods, such as fresh fruit and salads, nutty whole grains and lean meats, spend more time in your mouth, where saliva starts to breaks them down. This switches on your satiety signals in pace with you eating them.
4. Cheap as chips
Fat is just one of the many ingredients that manufacturers use to bulk up their products, which can then sell for more than the lighter, non-processed foods. Consider the fish finger or battered or crumbed fish. “Once, you had a fish fillet. However, breadcrumbs and oil are cheaper than fish; add them and you can sell a bigger thing for more. Now they’re making low-fat crumbed fish!” says food technologist Gary Kennedy from Correct Food Systems.
Fish fillets were the ultimate low-fat food, he says, “but adding fat makes them more desirable, and cheaper”.
5. Fat is a seductive secret ingredient
We rarely look for the nutrition information for foods we buy at bakery chains, fast-food courts, cafés and takeaway outlets. So, without us even realising, food manufacturers can boost their foods’ flavours and textures with fat, salt and sugar in quantities that can leave us wanting more.
Consider the cake-shop cake you bought for an office birthday party that you serve in generous slices. The cake itself and the icing are made with plenty of butter (fat) and sugar – and the reward is a double-dose of bliss. No wonder it’s hard not to go back to have a second slice.
How to train your taste buds
“We have to enjoy our food, and chocolate, hot chips and cake can have a place in your diet,” says Kate Gudorf, spokesperson for the Dietitians Association of Australia. The secret is to:
Really enjoy small amounts of your favourite fatty foods
Share a bucket of chips between three of you, break off just three squares of chocolate, cut a sliver of cake. Then savour your treat — smell the aroma, nibble at the crispness, roll the fat on your tongue. And eat slowly.
Broaden your palate beyond fat, salt and sugar
There are other intense flavours that will linger on your tongue given the smallest amount of fat. For a breakfast idea, make porridge with bananas, grated orange zest and low-fat milk, and sprinkle with toasted sunflower seeds. For lunch, add fresh mint and dill to salad made with a little olive oil dressing. And for dinner, stir-fry chicken mince with lemongrass, onion and garlic and add to lettuce leaves.
Train your taste buds to like other flavours
Associate Professor Keast confirms that if you like, say, deep-fried foods, “you can train yourself to like other types of food, but you’re still going to like deep-fried foods. We’ve never been able to affect preference, but we can affect sensitivity — that is, we can promote satiety [and pleasure in food] with less consumption of fat.”
Chew the fat
It’s a fact: a doughnut is not as satiating as a meal that contains protein and fibre. In the 1990s, dietitian Dr Susanna Holt conducted studies with nutritionist Professor Jennie Brand-Miller, establishing that “the more fibre, protein and water a food contains, the longer it will satisfy you.” So when we feed that snack impulse with a doughnut, the pleasure lasts as long as the delicious fatty flavour coats our taste buds.
Dr Holt tested 38 foods and ranked them in what became known as the Satiety Index. Here are examples of the least and the most satisfying foods, according to the index.