Is fat better than sugar? How these foods can affect weight loss

Eating a varied diet that includes a diverse range of fats, carbohydrates, proteins and, yes, the occasional sugars is the perfect way to eat and live well. But there has been an enormous amount of misinformation born out of the dreaded diet industry, particularly about fatty foods.

Fat-free products have been peddled as the "healthier" option for years and years. Think of all the advertisements you saw for "fat-free" foods that promise weight loss, proudly exclaiming that a particular milk has "only 10% fat", or a humble muesli bar is fat-free, therefore the better and healthier option.

Or, rather, the option that will help you lose weight. Fat-free yoghurt even became the butt of a joke on Seinfeld during the fat-free craze of the '90s.

But how does fat actually affect weight loss? Does eating a low-fat diet mean a steady path to losing weight? What about trans fats? But by avoiding fat, what are our bodies missing out on? And, how does eating fatty foods compare to eating sugary foods?

A history of the low-fat diet industry

Fat and sugar are the 2 hottest topics in diet culture. For a very long time, there was a cultural shift in the diet industry positing that "fat" was the evil culprit we needed to avoid in order to fight weight gain.

This is largely due to the messaging from doctors in the 1970s: people, particularly men over the age of 50, needed to eat less fat in order to lower their cholesterol and therefore lower the risk of heart disease.

As a result, this messaging exploded into a boom of misinformation about fat in foods, and it got a very bad rap. Instead of eating milk, cheese, avocados and fatty meats, people started replacing fat with carbs.

Now, doctors were actually suggesting people get their daily carbohydrates from whole grains, fruit and vegetables. But of course, this kind of messaging trickles down to the simple binary for non-medical people: carbs were in, fat was out.

The food industry changed dramatically, with the rise of low-fat, high-carb products stocking shelves and taking centre stage. Fat-free frozen yoghurt, muffins, cookies, cheeses, bottled salad dressings, drinks — there was barely anything left that didn't offer a low-fat or fat-free version.

This meant the formula for many diet-labelled foods quickly turned into taking the fat out and adding lots of sugar [1].

We were all led to believe in the health benefits of eating exclusively low-fat foods throughout the '80s, '90s and 2000s [2]. The guidelines do not suggest people reach exclusively for low-fat and no-fat products anymore. In trying to combat heart disease by extolling the virtues of a low-fat diet, we forgot about the importance of good fats in a balanced, healthy diet.

Unsaturated and saturated fats

Fat has a bad reputation, but it's actually vital for our bodies on a cellular level. Quite literally, eating fat helps create our cell membranes and the sheaths surrounding nerves. It is essential for minimising blood clotting, and muscle movement, stopping inflammation and providing energy [3].

But not all fats are the same, and which fats you choose will have a huge effect on weight loss.

Unsaturated fats are the good fats: the healthy kind that are going to give you the most efficient and strong cell growth. They differ from saturated fats by having fewer hydrogen atoms bonded to their carbon chains [3].

There are 2 types: monounsaturated (e.g. found in avocado, peanut butter, olive oil and most nuts and seeds) and polyunsaturated (e.g. oily fish like salmon, mackerel and trout).

Unsaturated fats actually keep cholesterol and blood pressure under control.

Saturated fat intake is a bit of a grey area in terms of helping with weight loss. It's the in-between — there are foods that are high in saturated fat and foods low in saturated fat. High-saturated fat is the one you want to minimise.

Common sources of saturated fat include red meat, whole milk and other whole-milk dairy foods, coconut oil, and many commercially prepared baked goods and other foods.

Is sugar or fat worse for weight gain?

It's now sugar, not fat, that has come into the limelight as the villain of health and more specifically, weight loss. There is a wealth of evidence proving links between sugar and obesity as well as other issues.

When we mention a high sugar intake, this means regularly eating sugary foods like donuts, cake, chocolate, and soft drinks regularly. Now, it's impossible to avoid sugar completely, as it occurs naturally in foods containing carbohydrates including fruits, vegetables, grains, and dairy. But, consuming whole foods that contain natural sugar, rather than added sugars, will help keep you healthy.

It is these added sugars that are considered not so healthy. You will find added sugars in a huge number of packaged products and processed foods like energy drinks, tomato sauce, breakfast cereals, fruit juices, iced tea, flavoured coffees, canned fruit and, yes, almost all low-fat foods [4].

Why is fat better than sugar?

Let's re-examine saturated fats to answer this question. Saturated fats seem to trigger insulin resistance in the same way that sugar does, meaning that your cells don't absorb glucose like they're supposed to. As a result, your body increases its output of insulin, a hormone that promotes fat in the body [5].

The "good" fats outlined above almost always involve eating nutritious foods like fish and avocado. Sugar only provides energy for our bodies, which is why we reach for those sugary snacks at 3pm on a workday to get through the mid-afternoon slump.

Diets that are low in carbs but high in fat are now widely regarded as being healthier, thanks to fat's help in controlling blood glucose levels. Fat is the most energy-dense nutrient and carries twice as many calories as the same weight of carbohydrates [6].

What about low-sugar diets?

In the sugar vs fat wars, it seems the good fats win.

A low-sugar diet combined with complex carbohydrates, good fats and protein is recommended for people trying to lose weight. Avoiding processed foods is also the way to go because even savoury foods can contain added sugars.

If you are going to take anything away from this, remember that not all calories are created equal. The great thing about calories from fat is that you will feel fuller for longer, meaning you won't be reaching for snacks as much and leading to a better chance of losing weight.

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Health coaching is used to assist you with lifestyle changes including sticking with a routine and a support system of other women on the journey with you, so you feel less alone, while one-on-one health tracking gives you a personalised experience.

Weekly check-ins with your health practitioner are used to track your physical, mental and biometric health, where adjustments can be made to suit your individual needs. If you want to be supported through every step of your weight loss journey, this is how to do it.

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