Fat is an established medical, political, and social issue across the globe and we can’t stop talking about it. From body shaming to chronic health problems, fat props up a whole industry of doctors, plastic surgeons, psychologists, media corporations, and food manufacturers, to name but a few.
What’s more, it’s just been revealed that 1 in 5 of the world’s population are likely to be obese by 2025. In a digital environment saturated with misleading and conflicting information, our doctors cut through the noise to give you the bottom line on fat.
What is fat?
Fat is a general term for a collection of different nutritional units belonging to the ‘lipids’ group. They act as storage vessels for a number of different fatty acids.
There are many different types of fat, although all have a very similar chemical structure made up of carbon and hydrogen bonds. Slight variations in the length and shape of these chains of atoms, as well as the number of hydrogen atoms they contains, determine how fats behave in your body.
Whilst certain fats can only be obtained from food (essential fats), the human body also produces fat from the nutrients we absorb.
Role of fat in the body
Fat is an important dietary ingredient and serves a multitude of essential bodily functions, some of which are listed below:
- Important energy source
- Means of storing energy
- Helps absorb minerals and vitamins A, D, E and K
- Facilitates nerve function
- Essential component of cell membranes
- Required to clot blood and move muscle
- Aids hormone production
Saturated vs unsaturated
Fats can be largely divided into saturated and unsaturated categories. This simply refers to how many hydrogen atoms are contained within a fatty acid chain.
Saturated fats have a full chain of hydrogen atoms (they are ‘saturated’ with hydrogens) and are straight in shape, making them solid at room temperature. Unsaturated fats have lost some of their hydrogen atoms and their chains bend, causing them to be liquid at room temperature.
The huge amount of saturated fats contained within modern western diets is largely responsible for the negative perception we have of fat, and the government has urged citizens to replace saturated fats with unsaturated ones where possible.
But does saturated = bad and unsaturated = good? The division isn’t so clear: trans fats – one of the worst health offenders – are actually a form of unsaturated fat.
Is fat good or bad?
Fat isn’t inherently ‘bad’ and, as listed above, fat is an essential nutrient needed for several bodily functions. Problems only occur when we exclusively eat a few types of fat in great quantities.
Consuming certain fats can bring tangible health benefits. A diet containing monounsaturated and polyunsaturated fats, for example, can encourage good heart health and lower levels of dangerous LDL cholesterol.
It’s important to remember, however, that fats are energy-dense: 1g of fat contains 9 calories, whereas 1g of protein or carbohydrate contains only 4 calories. As such, if you eat too many fats you might take on more energy than you can expend, leading to weight gain. To avoid this, try limiting your daily fat intake to 70g or lower.
A diagnosis of a fat as ‘good’ or ‘bad’ is too reductive and simplistic. Fat benefits depend on the sum of many different characteristics, and no one factor in isolation determines whether a fat is healthy or unhealthy. For example, while you may have heard long-chain Omega 3 fats are great for your health, consuming too many long-chain Omega 6 fats can pose health problems.
See our simple digest of the main types of fat and what they mean for your health:[restabs alignment=”osc-tabs-center” responsive=”false” tabcolor=”#166729″ tabheadcolor=”#000000″ seltabcolor=”#669900″ seltabheadcolor=”#000000″] [restab title=”Polyunsaturated fat” active=”active”]
Polyunsaturated fat | Good
Description: As the name suggests, polyunsaturated fats belong to the unsaturated fat family. They are made up of two main types: omega-6 and omega-3 fatty acids. They are essential fats, meaning they are required for basic bodily functions and can only be obtained from your food (the body cannot produce them itself).
Health Impact: This essential fat has been linked to a whole host of health benefits, from protecting against heart disease and stroke, to raising ‘good’ cholesterol and aiding child development via breastfeeding. Omega-3 fatty acids in particular can help reduce blood pressure, prevent blood clotting, and even regulate your heart’s rhythm.
Doctor’s advice: Whilst omega-6 can be great for your health, you only need a small amount of it. Contrastingly, try and get more omega-3 into your diet by aiming to eat at least two portions of oily fish a week. If you’re looking to lower your ‘bad’ cholesterol levels, start replacing saturated fats with polyunsaturated ones.
Found in: Corn, sunflower and safflower oils, walnuts, flaxseeds, oily fish (e.g. salmon, herring, mackerel, sardines).[/restab] [restab title=”Monounsaturated fat”]
Monounsaturated fat | Good
Description: Monounsaturated fats also belong to the unsaturated fats group. Whereas polyunsaturated fats have many unsaturated bonds, monounsaturated fats only have one.
Health impact: Monounsaturated fats are a founding nutritional pillar behind the ‘Mediterranean diet’ theory, which has been linked to a reduced risk of heart disease.
Doctor’s advice: Try and incorporate more of these types of fat into your diet along with polyunsaturates. It’s a good idea to substitute cooking oils high in saturated and trans fats with polyunsaturated varieties. Olives are also a great source of monosaturates.
Found in: olive, rapeseed and sunflower oils, avocados, most nuts, peanut oil.[/restab] [restab title=”Trans fats”]
Trans fats | Bad
Description: Whilst naturally occurring trans fats exist, the biggest health concern relates to man-made trans fats. This type of fat is a by-product of an industrial food production process called hydrogenation. This process turns liquid fats into solid fats, and helps extend the shelf-life of many different food products. Almost all processed foods will contain some form of trans fat.
Health Impact: There is no evidence suggesting trans fat has any positive health effects. On the contrary, it has been shown to increase your risk of developing heart disease, type 2 diabetes, and strokes. This is largely due to its effect in raising ‘bad’ cholesterol (LDL), lowering ‘good’ cholesterol (HDL), encouraging insulin resistance and causing inflammation.
Doctor’s advice: Artificially-produced trans fats are the worst type of fat you can consume. Cut back on the amount of processed foods in your diet and look out for ‘hydrogenated’ or ‘partially hydrogenated’ ingredients on food labels.
Found in: vegetable oils, margarines, fried food, crisps, biscuits, pastries, doughnuts, some meats, dairy products.[/restab] [restab title=”Saturated fats”]
Saturated fats | OK in moderation
Description: Saturated fats have a full chain of hydrogen atoms. Most come from animal sources, such as meat and dairy products, and while saturated fats are not entirely bad, many of us are eating too many of them.
Health Impact: A diet high in saturated fat can boost levels of ‘bad’ cholesterol. Cholesterol is a substance produced in the liver from the fats you eat. Unfortunately, saturated fats encourage the production of the LDL variety of cholesterol, which can build up in your arteries and form blockages. This can increase your risk of associated health problems, including heart disease, stroke, and heart attacks.
Doctor’s advice: Try and cut down or swap them for unsaturated alternatives. Women and men should consume no more than 20g and 30g of saturated fat respectively each day. Check your food labels: foods high in saturated fat contain more than 5g of saturates per 100g; foods low in saturated fat contain 1.5g of saturates per 100g.
Found in: Palm and coconut oil, butter, ghee, lard, cheese, cream, cream, whole milk, pastries, cakes, biscuits, savoury snacks, pies, sausages, fatty meats (beef, veal, lamb, pork).[/restab] [/restabs]
How to reduce body fat
Losing weight is a complex biological process. Our ability to burn and store calories depends on a network of metabolic processes, appetite control messages, and enzymes, all of which differ from person to person and can be influenced by particular lifestyle choices.
Nutritional biologists are increasingly stressing the importance of ‘the microbiome’ in our ability to lose weight. This refers to the unique make-up of bacteria living in our gut – there are about 100 trillion of them down there! The way they react to the food we eat is believed to directly affect how our body absorbs and releases energy. The Personalized Nutrition Project is leading this research, and believes that tailoring your diet to your bacterial ecosystem could help people lose weight and protect against problems like diabetes and Alzheimer’s.
It’s, therefore, hard to prescribe a one-size-fits-all approach to losing weight. However, limiting your portion sizes, maintaining a health balanced diet, and exercising regularly can all help reduce excess weight storage. Staying hydrated is also essential to the weight loss process.
Many people also use weight loss tablets to try and reduce their body fat. Given the rash of weight loss supplements with no scientific backing that exist on the internet, it’s hard to see the term ‘weight loss pills’ and not be sceptical. However, prescription weight loss medication administered by a doctor, such as Orlistat (Xenical), can be very effective; it works to reduce 25% of the fat absorbed during food digestion.
Some people consider aesthetic surgery, such as liposuction, with many increasingly turning to non-invasive body contouring methods. However, these methods only target fat just under the skin (subcutaneous fat). They do not affect deep fat surrounding our organs (visceral fat), which can increase our risk of a number of serious health problems – heart disease, type 2 diabetes, breast cancer, Alzheimer’s – if it is too highly concentrated.
Gastric bypass surgery is also available, but is treated as a last resort measure for obese patients for whom lifestyle changes and medication have failed. This procedure reduces the size of your stomach, limiting the amount of food you can ingest and making you feel full quicker.
Are low-fat foods healthy?
People worried about high cholesterol, maintaining a healthy heart, and looking to lose weight might be tempted by ‘low-fat’ alternatives to staple foods in their diets.
However, since fat brings a lot of flavour to food, many food producers increase the sugar content in low-fat foods to try and fill this void. They may also fill them with large amount of refined carbohydrates to add texture, but this can significantly boost the calorie content of the product.
Sugar will not give you the feeling of fullness that fat provides, so many people choosing low-fat options actually end up eating more to compensate. Eating huge amounts of sugar is itself not a healthy option and increase your risk of developing type 2 diabetes. Always check the sugar and carbohydrate content of low-fat jarred sauces, mayonnaise, soups and snack bars – their health credentials are often no better than those of the original product.
It’s also worth mentioning that the act of eating fat does not make you fat. Weight gain will occur if you consume an excessive amount of fat: your body has no immediate use for the energy you’ve taken on and thus stores it for the future. However, this rule applies to eating excessive amounts of protein and carbohydrates just as much as fat. Fat should not be treated in isolation or thought of as the main culprit in weight gain.