I have just been listening to a heated argument on Radio 4’s Today programme… and it’s one that is not going to go away anytime soon: the report, published jointly by the UK’s National Obesity Forum and Public Health Collaboration is about whether saturated fats are OK in our diets, and more. Let’s look at what’s been said, and why.
Types of fat
First, let’s look at what types of fat there are. There are four types of natural fat, saturated, mono-unsaturated and polyunsaturated and, less commonly, natural transfats; we also have unnatural transfats which are sadly far too common.
All natural sources of fat contain a mix of saturated, mono-unsaturated and polyunsaturated, just in different proportions.
This means that the fat on meat is not all saturated, and nor is all the fat in sunflower oil polyunsaturated. This is shown in the picture, left, by Xyzzy n.
Also, have a look at picture at the end of this brief article to see more examples of what foods contain what proportions of the fats.
We’ll have a quick look at the porperties of the different fat types, but for more detail, click here to read about the structure of different types of fat.
Foods high in saturated fats (such as butter or the fat in meat) are solid at room temperature. Because they are stable, they are ideal for cooking with.
Once inside our bodies, as well as providing us with energy, saturated fats (and there are many types) have many uses.
You will be familiar with olive oil which is high in monounsaturates. Oils high monounsaturated fats, like olive oil, are generally liquid at room temperature and solid in the fridge. They are fine for cooking a low to medium temperatures and have a range of uses in our bodies.
Polyunsaturated fats are unstable, spoiling with heat and light. These oils are found mainly in seeds, such as sunflower, flax and pumpkin seeds, and these are the ones the health authorities have been telling us to cook with… and thereby helping us add to bad health! Why’s that? Well:
Producing these oils on a commercial basis is done by chemical means (I won’t spoil your breakfast, but feel free to look up how), so they are stripped of much of their nutritional value;
Cooking with these oils at anything other than a very low temperature denatures them so they turn into harmful transfats;
Eating so much of these oils means we eat too many pro-inflammatory omega 6 fatty acids in proportion to anti-inflammatory omega 3 fatty acids (found mainly in oily fish and flax) which is bad for our health.
Eating a diet high in polyunsaturated fats helps contribute to a bad blood profile, heart problems and other health problems (including obesity), especially if you are eating a diet high in starchy and sugary carbohydrates too.
We do need some omega 6 fatty acids (as we can’t make them in our bodies), but these can be supplied through eating whole vegetables and fresh seeds.
We get natural transfats in some foods like butter – they have a role to play and are not harmful. BUT a different, harmful sort of transfat is created through hydrogenation of oils to make them solid and, you may be surprised to learn, saturated. They are used in margarines/spreads and in processed foods; they are also produced when we overheat unsaturated oils, particularly when frying.
These cause all sorts of havoc in your cells and you need to be doing all you can to avoid them.
Why are oils hydrogenated? They last a long time, so the foods which contain them (often too with sugars) have a good ‘shelf life’, and are cheap to make.
The national Obesity Forum’s Report
Thus, I am so pleased to hear about the National Obesity Forum and Public Health Collaboration’s joint report about the unnecessary vilification of fat. Let’s have a look at what was said:
Eating saturated fat does not make you fat
This is correct!
There is a caveat, however: eating saturated fats when insulin levels are low does not make you store fat. However, when insulin levels are higher because you have been eating sugar- or starch-based carbohydrates, then you can store fats if you eat both at the same time.
Put another way, you can only store fat in the presence of enough insulin; this means you can eat a meal like a fatty piece of meat with a creamy, buttery sauce along with a salad and you will use up the fats and not store them.
On the other hand, if you eat that meat along with some garlic bread, rice and a desert, your insulin levels will increase and some of what you have eaten will be stored as fat.
(When you eat carbohydrates – we are not counting fibre here – your body must use these up first, because too much blood sugar is toxic to your body. If there are any left over carbohydrates or fats, they are stored as fat.)
You should stop counting calories
This is right. Calories are merely an expression of energy. Coal and wood contains calories, and we don’t eat them. Well, eat them if you will, but you won’t get any usable energy out of them. It is the type of calorie you eat that matters. In addition, numbers of calories, while they make sense in a closed system (like a bomb calorimeter), they do not follow the lines of calories in = calories out when we eat and use them.
In fact, there are not exactly 3,500 calories in a lb of fat; it varies – and the 3,500 figure is based on…er… no-one knows: no-one can find the original calculation, nor any studies, nor why the figure has been taken as gospel. Ask any of the health authorities and they will not be able to answer you!
In addition, not all calories are treated the same in the body: it takes more energy to digest protein than sugar, for example, and the energy going into your body is partitioned differently: some will go for energy production, for example, some as an energy storage, and some for other metabolic needs.
‘Eat 3,500 fewer calories a week and you will lose 1lb’ is quite patently nonsense; for example:
You could, theoretically, fade away to nothing, and you don’t;
Your BMR (resting metabolic rate) just slows down if you really cut calories;
If you eat carbs (fewer calories) rather than fats, your insulin levels will stay elevated: this means you will not be able to access your fat stores and you will get hungry more quickly;
If you swap your portion of lamb or salmon (more calories, relatively) for a portion of toast, low fat spread and orange juice (fewer calories), you will carry on putting on weight (and getting energy crashes);
The soluble fibre found in vegetables, although ‘zero calorie because we can’t digest them’ are fed on by your gut bacteria… as a by-product they make fats, which do have available calories! However, don’t panic: these important short-chain fatty acids are used for energy, cholesterol balance and some even have anti-cancer properties.
Yes , that’s right: if you have a diet high in starches and sugars (fewer calories) you start overriding your natural ‘I have eaten enough and will stop eating now’ signals. This is partly because if you eat grain-based foods and sugars, you set up what amounts to an addiction and crave more of the same; it is also partly due to building up insulin and leptin resistance, and partly to do with other factors cause by a high carb, grain based diet.
Running will not help you lose weight
Obesity is a hormonal disorder, and increasing exercise in order to lose weight will either:
Drive you to eat more (hence the phrase, ‘Let’s walk up an appetite’), or
Make you move less the next day or so.
Another way people try to lose weight is by cutting their calories a lot. This is a huge subject which can’t be dealt with here but, if you go on a long-term calories restricted diet you will either:
Move less (you will get tired); or
Eventually be driven to eat
In fact, eating fewer starches and sugars and more saturated fat will both help you with energy levels and lose weight.
a) Saturated fat does not cause heart disease, and b) full-fat dairy is likely to be protective
New meta-analyses of the evidence available forty years ago does not support dietary fat restrictions, and nor do many more recent studies; indeed, many studies show the opposite to be true.
Additionally, for those not lactose- or casein-intolerant full fat dairy has been shown to be ‘protective’to health. At the very least it is a good source of saturated fats, vitamins A, D, E and K, calcium and, in some grass fed A2-type dairy products, omega 3 fatty acids.
Avoid processed foods labelled ‘low fat’, ‘lite’, ‘low cholesterol’ or ‘proven to lower cholesterol’
Trawl the studies and meta-analyses out there (I have) and you will not find any evidence demonstrating reducing dietary saturated fat reduces atherosclerosis and other cardiovascular problems. Neither will you find anything saying saturated fat increases cholesterol.
(But, and here’s a tip, a high carb diet increases the so-called ‘bad cholesterol’ or, more properly tiny, dense LDL particles which are cholesterol carriers. The larger, less dense, more ‘fluffy’ LDL particles are produced when we eat meals based on fatty foods and vegetables, and not grains or sugars.)
While we’re on the subject of cholesterol, understand this is vital for life: without cholesterol you would die. If you don’t eat foods containing cholesterol, your body simple makes it. There’s been a lot of misinformation about cholesterol and that’s the subject of other posts and also looked at in my book.
For now, suffice it to say that ‘bad cholesterol’ is a) in fact oxidised cholesterol carried in dense, tiny carriers which can get stuck in inflamed artery walls, and b) created when eating a diet high in carbohydrates (especially grains and sugars) and transfats (created from heating vegetable oils). It is not created by eating foods high in saturated fats and/or cholesterol.
Snacking will make you fat
In the main, yes, this is true. Of course, there are caveats:
If you eat fatty snacks such as nuts, olives, cubes of mature cheese, ham wrapped in lettuce, etc, you will generally eat what you need, and you won’t be storing fat;
As you begin to access your fat stores you will need to snack less – you are getting food from inside you;
If you snack on low calorie foods (which will be are starchy and/or sugary), they hit your blood stream quickly, so your insulin levels increase quickly too… and you end up a) storing the carbs you have eaten, b) not being able to access your fat stores, c) having an energy crash (so you need to eat more), d) not getting all the nutrients you need, and e) not sleeping so well (and good sleep is needed for a healthy weight).
Those with Type 2 diabetes should eat a diet rich in fat instead of a diet based on carbohydrates
In the days before insulin, diabetes was controlled through diet… but not the high carb, low fat diet recommended by today’s Diabetes Association and other groups, but a low carb, high fat diet. Guess which one worked? Today’s diabetics are told to eat carbs regularly throughout the day to keep blood sugar levels on an even keel. Well, they’re kept level to an extent, but at too high a level, meaning insulin levels are also kept higher.
This leads to insulin resistance (so they don’t let glucose in) and leptin resistance (so we don’t get ‘full’ signals) which in turn lead to an increase in weight and/or diabetes. Just to add to the body horror, cereal and sugar based carbs beget carb cravings… and a normal blood sugar-energy cycle starts spiralling into chemical chaos.
Health authorities do go so far as saying eat less added sugar (they are too cowardly to say ‘cut it out’), but at the same time encourage the consumption of ‘healthy’ grains, especially whole grains… and seem to miss the point entirely that starches (a huge proportion of these grains) digests into glucose! In fact, because they contain amylopectin A, a fast-digesting carbohydrate, blood sugar levels increase more with grain consumption than they do with eating sugar!
Following a low carb, high fat diet, however, keeps insulin levels down and cells retain their insulin sensitivity meaning they can let circulating glucose in. This means muscle and organ cells get the energy they need (you feel better for it too), but there is less glucose left to be shunted into your fat cells.
(NOTE: Glucose can’t just be left to hang around in the blood: if excess glucose is left circulating, one develops type 2 diabetes and complications such as damage to eyesight, kidneys and limbs occur.)
Neither will you be missing out on vital nutrients: yes, some good ones are available in wholegrain bread and the like… but:
We can get these nutrients elsewhere (in seafood, fish, meat, organs and vegetables);
Grains contain chemicals called lectins (including wheat germ agglutinins) which block the efficient absorption of several nutrients, including iron and zinc;
Grains contain some other nasty natural chemicals including phytates, alpha-amylase inhibitors, glutenins and gliadins (which together make gluten), all of which have a harmful effect on your gut lining and body health.
On the other hand, a diet high in fats (from meats, fish, seafood, nuts, coconuts and avocados and not vegetable seed oils), with leafy vegetables and moderate amounts of sweeter vegetables (not sweet corn; that is a grain), will keep blood sugar levels stable for most people with type 2 diabetes without the need for metformin and insulin injections… and prevent others from getting it in the first place.
Does the report go far enough? I don’t think so, but we are getting there.
In summary, then:
1. Saturated fats are good for you
2. Polyunsaturated fats should not be eaten unless in their natural form
3. Eat real, not processed food, and your energy health will return
4. As your body starts healing from the inside out, you will lose fat
Hope that helps!