We place a lot of emphasis on the number of calories in our diets as this is central to our weight loss success, however we mustn't overlook the importance of the nutrients we need too. After all, the food on our plates is made up of different nutrients in varying proportions – calories are just the total energy they all provide.
To help you understand a little more about the nutrients in your food and why they're so important, we're putting together the ultimate series of nutrient guides to bust the myths and equip you with all the nutritional know-how you need to make informed choices about your diet and your health. We’ve covered carbohydrates, protein, fibre, sugar and salt so far – now, we're looking at...fat!
Fat is a macronutrient found widely in our diets. We find fat in the membrane of every cell in our body, and it plays an essential role in our brain health, hormone production and absorption of certain vitamins. It can also be used as a source of energy alongside carbohydrates. There are several different types of fats found in our diet, each of which has its own unique influence on our bodies.
Although we’re not a fan of labelling foods as ‘good’ or ‘bad’, we know different types of fat have different effects in our bodies.
When talking about fat, many of us jump to thinking about cholesterol and heart health. It’s true that dietary fat has a significant influence on our cardiovascular system. Eating lots of saturated fat has been shown to increase our cholesterol levels, in particular a type called LDL cholesterol. This has been branded the ‘bad’ type of cholesterol, as having high levels of LDL cholesterol in the blood over time can increase the chance of our arteries getting clogged up by fatty plaques. This is when heart disease can progress, and negative cardiac events like stroke and heart attack are more likely to happen.
On the other hand, unsaturated fats raise a different type of cholesterol, called HDL cholesterol. HDL cholesterol helps to remove excess cholesterol from the blood and lower levels of LDL cholesterol, plus it may also have anti-inflammatory and antioxidant properties too. So eating the right type of fat may actually have a positive effect in protecting heart health and keeping cholesterol levels in a healthy balance.
As we touched on above, we can categorise unsaturated fats as either mono- or poly-unsaturated fats. While mono-unsaturated fatty acids (found in olive oil and avocados) still have excellent health benefits, our bodies are able to synthesise them if needed. On the other hand, poly-unsaturated fatty acids must be sourced through our diet, making them an essential nutrient. You might have heard of omega-3s before – these are one of the most important types of poly-unsaturated fatty acids. Studies continue to associate omega-3 fatty acids with slower cognitive decline as we age, as well as a decreased risk of Alzheimer’s disease if we eat them regularly in our younger years. Plus, we use poly-unsaturated fats for blood clotting and also as part of our immune response.
We can find poly-unsaturated fats in oily fish, and also in walnut and canola oil. If you don’t include many of these foods in your diet, you might want to consider an omega-3 supplement. Fish oil is the most popular, but there are also plant-based supplements available.
Back in the 1970s, the notion that fat was to blame for overweight and obesity first came about due to the introduction of low-fat dietary guidelines. Although more modern diet trends have shifted the spotlight from fat to carbs, the decades-long negative press that fat has garnered means it still maintains a lot of its notoriety today. Now we know that in terms of weight loss, the most important factor is ensuring your calorie intake is lower than the calories burned by your body (known as a calorie deficit). Providing you are in a calorie deficit, the nutrients you choose to consume play less of a role.
That said, there is a reason why people who follow a lower-fat diet might see weight loss. Gram from gram, fat contains 9 calories, which is more than double the calories found in protein and carbs. This means that 100 calories worth of a high-fat food will typically be a smaller portion compared to 100 calories of a high-carb or high-protein food. Take olive oil for example – 1 tablespoon contains 123 calories, which is the equivalent to a 200g bowl of fat-free Greek yoghurt, or 30 strawberries!
Now just because fat is more calorie-dense than other nutrients, this doesn't mean it should be cut out of our diets. We know unsaturated fats are good for us, and many foods rich in these fats also provide us with other nutrients, such as vitamins A, E, D and K. Plus, foods with a bit more fat are often really tasty! For these reasons, we shouldn’t be denying ourselves of fat, even when trying to lose weight. The key here is portion control. Including small portions of different sources of healthy fats regularly throughout the week and moderating intake of saturated fats can strike the balance between the amazing health benefits of fats and sustainably maintaining a calorie deficit.
In the wake of the low-fat trend, we can see the huge influence it’s had on the products available on supermarket shelves. Health claims of ‘low-fat’, ‘fat-free’ and ‘diet’ appear in big bold letters on the front of spreads, yogurts, cheeses, crisps and ready meals. But are these products a better choice? On the surface, these options are lower in calories, so could be more helpful for maintaining a calorie deficit compared to their full-fat counterparts. However, fat is often essential for textural and flavour reasons, so when manufacturers remove fat from a product, they need to add something back in to replace it. This is usually a combination of additives to mimic the flavour and mouthfeel of fat, but the biggest culprit, especially for dairy products, is usually added sugar. We should be aiming to keep our added sugar intake down (read why here), so to make the best choice for weight loss, be sure to check the ingredients list of your fat-free choices and look for sugar on the label. It’s best to opt for fat-free products with ‘no added sugar’, or consider enjoying a smaller portion of the full-fat version – it may help you feel fuller.
For health, the UK government recommends that no more than 35% of dietary energy comes from fat. For a 2000-calorie diet, this would be around 78g of fat per day. For someone on a reduced daily intake of 1400 calories, this would be 54g per day, although this number will vary depending on your calorie target.
The recommendations further outline that a maximum of 11% of our calories should derive from saturated fat. So of the 78g recommended fat intake for a 2000-calorie diet, a maximum of 24g of this should be saturated fat.
In line with these recommendations, our Well Balanced nutrient goal will automatically set your fat target to 35% of your calorie intake, although it isn't necessary for you to reach this number each day. The Nutracheck app also tracks saturated fat alongside total fat, to help you keep an eye on your intake. The Well Balanced goal sets your saturated fat to 11% of your calorie target, however this is an upper limit, not a target.
Despite the surge in popularity, it's important for you to think about whether a low-fat diet is the best approach for you personally. If you find that eating a little less fat helps you to stick to your calorie deficit by giving you larger portions, go right ahead! However, if you find yourself missing higher-fat foods from your diet, or perhaps you’d rather keep your target for other nutrients lower, such as carbs, then don’t feel any fear or pressure not to enjoy more fat-rich foods!
If you're interested in trying a lower-fat diet, the Nutracheck app has a pre-set nutrient goal that automatically sets you a reduced fat target in line with your calorie target.
The 'Lower Fat' nutrient goal brings your fat target down from 35% to 25%, and subsequently brings your protein and carbohydrate targets up a little to compensate.
To set yourself the Lower Fat nutrient goal in the Nutracheck app, tap the blue menu button next to the search bar in your diary, then select 'Nutrient Goals'. Choose the 'Lower Fat' goal from the list. Save your changes by tapping 'Set this goal'.
On the Nutracheck website, click 'Settings' from the menu at the top of your Diary page, then 'Set a nutrient goal'. Click the 'Lower Fat' goal from the selection, then click 'Apply Changes' to save your new settings.
Nutritionist Amy Wood (ANutr), MSci BSc Nutrition has a keen interest in the relationship between diet and health. Having been published in the European Journal of Nutrition, Amy is passionate about making evidence-based nutrition accessible to everyone and helping others to adopt a food-focused approach to taking control of their health.