Whatever you call it, some fat is good for us — provided it’s right type

WE received an email at the surgery recently from a patient who was querying our use of the phrase “weight management” in some of our practice communications.

In doing so, they were not only challenging us on the use of the proper terminology but also by extension challenging the wider NHS, the healthcare sector and society as a whole.

Their criticism is technically correct — weight refers to the amount of gravitational force acting on an object, measured in newtons, and so changes according to the object’s location and movement in relation to other bodies. Mass, on the other hand, is measured in kilograms and is the measure of the amount of matter within an object, so actually we and everyone else should be talking about mass management.

We should be complimenting people on how much mass they’ve lost or talking about the latest mass loss drugs on the market. We should not be talking about weight.

And yet we still do. It’s so ingrained in our vernacular that to change it would be like suddenly stepping into an alternate dimension.

There are lots of other things that we say that we know aren’t quite right or accurate but, for ease of use, we persevere with.

The word “fat” is one of those things. If you will excuse the pun, our language is saturated with words that may or may not mean the same as fat.

Fatty acids, cholesterol, triglycerides, adipose tissue — the list goes on. Fats are members of a broad group of chemical compounds known as lipids. The word itself comes from the old English verb “to cram” or “to load”.

While it is no longer a verb, it has evolved into an adjective to describe someone, perhaps rather maliciously, as overweight or obese.

But it also refers both to the tissue within our body that protects our organs and insulates our internal environment from the outside and to one of the key dietary components which we take on board when we eat.

Lipids, of which cholesterol is just one example, are characterised by certain chemical and physical features, one of the most important being that they are not soluble in water.

You can see this best in oil, a fatty substance, that forms blobs within and on the surface of water rather than dissolving in it. The world of lipids is an ever-changing complexity of components derived from food moving around the blood stream to places like the liver and the adipose tissue where they are stored.

Each lipid has a specific role. Phospholipids, for example, are mostly found forming cell walls, putting their fat insolubility to good use (a dissolving cell wall after all would not be much use).

Cholesterol also has a role to play in cell membranes as well as complex jobs in cell processing and as a precursor in certain pathways that synthesise vital components that we need to function.

Despite these vital functions, our perspective on lipids is an interesting one. Even going back to the old English meaning of fat, there is a connotation of excess.

But our ancestors would have had limited and scarce access to sources of fat in their diets, so that when they were able to find a source, it was not wasted.

After all, we need fat. When it is stored within our bodies in adipose tissues (made up primarily of adipocytes, or “fat cells”) it cushions and protects our bodies.

More than that, it provides us with energy. One gram of fat provides us with nine kcal of energy as opposed to four kcal provided by an equivalent amount of carbohydrates or protein.

And the fact we can store it is (or was) hugely advantageous to humans who weren’t sure where their next big meal was coming from.

Now we also know that adipose tissue does more. In 1994, scientists discovered that a protein hormone called leptin was secreted from adipose tissue. This is a hormone that sends signals to the brain to tell us how hungry we are.

Since then, further research has revealed several key hormones secreted from fatty tissue that have impacts upon blood pressure control, stimulation of new blood vessels, regulation of insulin, stimulation and control of inflammation and many other things.

Keeping adipose tissue and levels of fat within a healthy range therefore has knock on effects for the whole body.

The thing is, now you can’t move for fat. Obesity is one of the foremost health issues in our modern world, not helped by poor levels of physical activity and epidemic levels of processed foods.

Furthermore, sugar (a carbohydrate that is converted to fat when not immediately used to avoid building up within the blood stream) is consumed in such excess, due to commercial greed, that not only is it affecting levels of obesity but it is also causing type two diabetes mellitus to rank alongside obesity as a massive health issue.

It is little wonder that associated conditions such as heart disease and cancer are such big problems. As of 2023, 64 per cent of adults in England were estimated to be overweight or obese. It is vitally important that this trend is reversed.

There is a rough target for the amount of body fat percentage we should be aiming for. Our body mass is composed of roughly 60 per cent water and seven to 15 per cent bone. The remaining 25 to 33 per cent is primarily made up of muscle and fat.

An elite athlete most likely sits at a body fat percentage of between six and 13 per cent for males and 14 to 20 per cent for females. For the average adult male 18 to 24 per cent is acceptable and for females the figure is more like 25 to 31 per cent.

The gender discrepancy is largely related to hormonal differences that cause more subcutaneous (under the skin) fat deposition in areas in the hips, buttocks and thighs.

Subcutaneous fat is not associated with cardiovascular risk or cancer.

Visceral fat, on the other hand, is. Visceral fat is adipose tissue within the abdomen that lines the organs and in excess causes central obesity. It’s more common in men, hence higher rates of heart issues in men.

Excluding fat from the diet altogether is not the answer. You have probably heard the terms saturated and unsaturated fats but it is not always clear what this means.

Put simply, the terms saturated and unsaturated refer to the lack, or availability respectively, of binding points for certain molecules on the chemical chains of the fat.

Saturated fat is bad. Unsaturated fat is good. Why? Among other things, unsaturated fats tend to stay liquid at room temperature while saturated ones tend to be more solid, therefore clogging things up.

Unfortunately, saturated fat is found in lots of the tasty stuff like cheese, butter, pizza, biscuits, beef and pork. It lines our supermarket aisles and surrounds us as we pay for our petrol.

Switching to a diet full of unsaturated fats, however, pays huge dividends and could add years to your life. Nuts, seeds, avocado and oily fish like salmon, trout, herring and mackerel are much healthier, while olive oil, safflower oil and sesame oils are far preferable to saturated fat alternatives like butter, lard and highly saturated vegetable oils like palm oil.

It may seem obvious but any benefit from eating these is negated if you eat saturated fats as well. It is important to bear in mind also, of course, that you can have too much even of a good thing. A calorie is a calorie regardless of what food it comes from.

While it seems unlikely we will replace weight with mass in our everyday language (after all, you know what we mean), it is more important for us to address and alter the established norm in our modern diets.

After all, the right dose of fat is good for us — just as long as it is the right type.