Fat: why are we so confused about whether or not we should include it in our diet?

Jul 29, 2021

5 min

Dr Duane Mellor

You’d be forgiven for being confused about whether or not you should eat fat. For a long time, people were told to stay well away from it entirely. But lately, fat seems to be back on the table – but only certain types of fat.


With so many conflicting messages about which types of fat to eat, it’s no wonder many people are confused about whether or not they should it. Here are just a few reasons why the advice about fat is so confusing – and how much fat you should really eat.


Some fat is essential in our diet as it gives us energy and helps us absorbs certain vitamins, including vitamin A, D and E. But there are many different types of fats and eating too much of certain types can be harmful to us. Unsaturated fats (also called monounsaturated or polyunsaturated) are known as “good” fats and are important for helping us lower cholesterol and keep our heart healthy. Unsaturated fats can be found in foods such as avocados, olive or peanut oils, and fish.


But saturated fats can be bad for us when eaten in excess, and can raise cholesterol and increase risk of heart disease. Trans fats can also increase cholesterol levels. Foods that contain saturated and trans fats include butter, cheese, bacon, biscuits and fried foods.


Fat is important

Many health authorities worldwide agree fat is an important part of a healthy diet – but that we should only get so many calories daily from fats.

The World Health Organization (WHO) recommends people get no more than 30% of their daily calories from fat – of which only 10% of daily calories should be from saturated fats, and less than 1% from trans fats.


The UK’s recommendations are much the same, limiting saturated fats to only 10% of our daily calorie intake – around 30g per day for men (around 270 calories) and 20g for women (around 180 calories).


But in Europe, health recommendations suggest fat should comprise between 20-35% of our total daily calories. There’s also no recommendations for how many calories should be from saturated or trans fats – just that these should be limited. In the US, people are only advised to limit saturated fat intake to less than 10% of daily calories.


So while there seems to be agreement in how much fat people should eat, the slight variations in these recommendations – as well as variations in how much of certain types of fat we should eat – might explain the confusion over whether or not we should eat fat and how much of it we should eat.


Misleading advice

If all the different recommendations weren’t confusing enough, there’s also a lot of information out there that’s either too simplistic or incorrect. This makes the recommendations about eating fat all the more complicated.


For example, the Joint British Societies (which publishes recommendations to help people reduce their risk of cardiovascular disease) recommends that only around 10% of a person’s total fat intake should come from saturated fats. As typically we consume 30-40% of our calories from fat, and international and government bodies recommend that around 30% of daily calories should come from fat, limiting saturated fats to 10% of this would mean they’d make up only 3% of our day’s calories. This would amount to little more than about 7g of saturated fat -– around two teaspoons of butter.


This differs from many other recommendations – such as from WHO – which states 10% of all the calories people eat daily should come from saturated fats. It’s also unclear whether such a strict restriction of saturated fats would have any benefit and would be difficult for many people to achieve as a variety of healthy foods – such as olive oil – can also contain saturated fats.


There’s also a lot of advice that’s too simplistic, which can be inadvertently misleading.


For example, one tip the British Heart Foundation recommends for swapping saturated for unsaturated fats is to use a spray oil or measuring oils, instead of just pouring it straight from the bottle.


But this doesn’t account for the fact that different types of oil have different saturated fat levels. Sunflower oil, for example, is already low in saturated fat, so using less would significantly reduce calories but only modestly reduce saturated fat levels.


Other advice from the British Heart Foundation includes avoiding frying foods and switching to semi-skimmed milk. But focusing on methods that have a minimal effect on saturated fat levels can make it more confusing to know which foods (and fats) to avoid. The easiest way to avoid saturated fats is avoiding foods like pies, cakes and biscuits. These foods are high in saturated fats and tend to be the greatest sources of them in most peoples’ diets.


Getting the right amount

Research suggests that we should get around a third of our energy from fat – two-thirds of which should be unsaturated fats.


Of course, certain food sources will contain different types of fats, and different levels of fats. For example, avocados and pies are both high in fat. But avocados are high in healthy monounsaturated fats, which are good for heart health and can lower cholesterol. Pies, on the other hand, are high in saturated fats, which can be bad for your heart and cholesterol levels.


The easiest way to make sure you’re eating enough of the right fats is to avoid foods that contain saturated and trans fats – such as butter, hard cheeses, pies, biscuits, pastries, cakes, processed meats and crisps. These foods are also high in salt, carbohydrates and sugar, so can also have other health harms such as increasing risk of high blood pressure.


Instead, try including sources of healthy fats – such as avocados, olive oil, nuts and fish. This will ensure that you’re not only getting enough fat in your diet, but that you’re getting the right kind of fats (around 75g a day for women and 90g for men).


Connect with:
Dr Duane Mellor

Dr Duane Mellor

Visiting Academic

Dr Mellor is an award-winning dietitian, science communicator, medical educator and researcher.

Food ScienceDieteticsDiabetesObesityNutrition

You might also like...

Check out some other posts from Aston University

2 min

How mitochondria shape brain health from childhood to old age

From the first spark of neural development to the challenges of ageing, Dr Lissette Sánchez Aranguren is uncovering how the cell’s powerhouses — mitochondria — hold the key to a healthy brain across the human lifespan. Her pioneering research at Aston University explores how these microscopic energy generators safeguard the brain’s communication network and how their dysfunction may underlie conditions such as dementia, stroke, and neurodevelopmental disorders. Mapping the brain’s energy defence system Dr Sánchez Aranguren’s work focuses on the partnership between brain cells and the blood vessels that nourish them — a relationship maintained by the blood–brain barrier. When mitochondria fail, that protective interface can weaken, allowing harmful molecules to penetrate and trigger inflammation or cell loss. Her team’s studies show that mitochondrial malfunction disrupts the dialogue between neurons and vascular cells, an imbalance seen both in the developing and ageing brain. To counter this, she and her collaborators have engineered a mitochondria-targeted liposome, a nanoscale “bubble” that delivers restorative molecules directly where they are needed most. By re-balancing cellular energy and communication, this innovation could one day reduce brain injury or slow neurodegenerative decline. From heart cells to the human mind Originally trained in cardiovascular science, Dr Sánchez Aranguren became fascinated by how mitochondria regulate energy and stress in blood-vessel cells — insights that ultimately led her toward neuroscience. View her profile here “Mitochondria do much more than produce energy. They send signals that determine how cells communicate and survive.” That realisation inspired her to trace mitochondrial signalling across the continuum of life — linking early brain development to later-life vulnerability. Her research now bridges traditionally separate fields of developmental biology, vascular physiology, and ageing neuroscience, helping identify shared molecular pathways that influence lifelong brain resilience. Global collaboration for a healthier brain Her work thrives on multidisciplinary and international partnerships. At  Aston, she collaborates with scientists from Coventry University, Queen’s University Belfast, and the University of Lincoln, alongside research partners in the Netherlands, Italy, Malaysia, and China. Together they integrate chemistry, biology, and computational modelling to understand mitochondrial function from molecule to organism — and translate discoveries into practical therapies. Towards mitochondria-targeted brain therapies The next frontier is refining these mitochondria-targeted nanocarriers to enhance precision and efficacy in preclinical models, while exploring how mitochondrial signals shape the brain’s vascular and neural architecture from infancy through adulthood. Dr Sánchez Aranguren envisions a future where protecting mitochondrial health becomes central to preventing brain disease, shifting medicine from managing symptoms to preserving the brain’s natural defence and repair systems. “If we can protect the cell’s own energy engines,” she says, “we can give the brain its best chance to stay healthy for life.”

2 min

From circular supply chains to global sustainability leadership: How Dr Luciano Batista is shaping the future of the circular economy

When it comes to transforming how organisations produce, consume, and reuse resources, Dr Luciano Batista, professor of operations management at Aston University, is a global pioneer. His research sits at the crossroads of innovation, digital transformation, and sustainability, tackling one of humanity’s most pressing challenges: our overconsumption of the planet’s resources. Reimagining the economy around renewal Dr Batista’s work focuses on circular supply chains —a model he helped establish at a time when 'closed-loop' systems dominated sustainability thinking. His early research laid the foundation for how businesses could move beyond recycling and linear take-make-dispose models, instead designing systems that reuse, restore, and regenerate.  View his profile here From theoretical frameworks to real-world applications, his studies—such as comparative analyses of circular systems implemented by Tetra Pak in China and Brazil—demonstrate the measurable economic and environmental benefits of circularity in action. His 2022 Emerald Literati Award-winning paper introduced a methodology for mapping sustainable alternatives in food supply chains, earning international recognition for its real-world impact. A global voice for industrial symbiosis and circular innovation The influence of Dr Batista’s work reaches far beyond academia. He has advised the European Commission’s Circular Cities and Regions Initiative (CCRI) and contributed insights to policymakers through the UK All-Party Parliamentary Manufacturing Group. His expertise continues to inform national and regional strategies for sustainable production and industrial symbiosis —where one company’s waste becomes another’s resource. Today, he extends that impact globally as a visiting professor at the Massachusetts Institute of Technology (MIT), conducting research at the MIT Center for Transportation & Logistics on circular supply chain innovations, supported by Aston University’s study-leave programme. He also mentors future leaders in sustainability as part of Cambridge University’s Institute for Sustainability Leadership (CISL). Driving the next wave of sustainable transformation Looking ahead, Dr Batista is spearheading collaborations through Aston’s Centre for Circular Economy & Advanced Sustainability (CEAS), working with the Energy & Bioproducts Research Institute (EBRI) and West Midlands Combined Authority (WMCA) on projects developing biochar-based clean energy systems for urban districts. He is also advancing the social dimension of the circular economy—ensuring that the move toward sustainable production is inclusive and equitable. His Symposium on the Socially Inclusive Circular Economy, held at the 2025 Academy of Management Conference, has sparked new international research partnerships with Monash University (Australia) and the Vienna University of Economics and Business. A vision for a regenerative future At the heart of Dr Batista’s work is a simple but urgent truth: humanity is consuming resources at a rate our planet cannot sustain. Through his research and global collaborations, he is helping organisations, policymakers, and communities move toward a future where growth and sustainability coexist. “The transition to a circular economy is not optional—it is essential,” says Dr Batista. “Our goal must be to redesign systems that allow people, businesses, and ecosystems to thrive together.”

2 min

Aston University’s Ian Maidment helps develop training for pharmacy staff supporting those with long COVID

The e-learning resource, Supporting people living with long COVID, was developed by the Centre for Pharmacy Postgraduate Education (CPPE) It is designed to help community pharmacy teams build their skills, knowledge and confidence The programme offers video and audio resources, practical consultation examples and strategies for supporting individuals. Professor Ian Maidment at Aston Pharmacy School has been involved in a project with the Centre for Pharmacy Postgraduate Education (CPPE) to develop a new e-learning programme for community pharmacists, called Supporting people living with long COVID. The programme is designed to help community pharmacy teams build their skills, knowledge and confidence to support people managing the long-term effects of COVID-19. It was developed with researchers undertaking the National Institute for Health and Care Research (NIHR)-funded PHARM-LC research study: What role can community PHARMacy play in the support of people with long COVID? During the development of the e-learning resource, as well as with Professor Maidment, CPPE worked in collaboration with researchers from Keele University, the University of Kent, Midlands Partnership University NHS Foundation Trust and lechyd Cyhoeddus Cymru (Public Health Wales). The research draws on lived experience of long COVID, as well as the views of community pharmacy teams on what learning they need to better support people living with the condition. This new programme offers video and audio resources, practical consultation examples and strategies for supporting individuals through lifestyle advice, person-centred care and access to wider services. Professor Maidment said: “As an ex-community pharmacist, community pharmacy can have a key role in helping people living with long COVID. The approach is in line with the NHS 10 Year Health Plan, which aims to develop the role of community pharmacy in supporting people with long-term conditions.” Professor Carolyn Chew-Graham, professor of general practice research at Keele University, said: “Two million people in the UK are living with long COVID, a condition people are still developing, which may not be readily recognised, because routine testing for acute infection has largely stopped. For many, the pharmacy is the first place they seek advice about persisting symptoms following viral infection. The pharmacy team, therefore, has the potential to play a really important role in supporting people with long COVID. This learning programme provides evidence-based information to develop the confidence of pharmacy staff in talking to people with long COVID. Developed with people living with long COVID, the programme’s key message is to believe and empathise with people about their symptoms.” Visit www.cppe.ac.uk/programmes/l/covid-e-01 to access the e-learning programme. This project is funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number NIHR205384).

View all posts