One of the topics we discussed on the health panel at BBC Berkshire the other day was whether low fat is good for us. Certainly my clients are surprised when I tell them they can eat butter and full fat Greek yoghurt.
The whole low fat conception stemmed from Ancel Keys’s study in the 1970’s -The seven-countries study, which highlighted certain countries that ate low fat and had low incidents of heart disease. However critics have said this study is flawed because it left out countries that showed the opposite, ie. high fat diets and low levels of heart disease. As a result, food manufacturers spotted a marketing opportunity and began developing ‘low fat’ foods, starting with fruit yoghurts (remember the Ski adverts in the 70’s), as well as the development of trans fats -chemically changed fats used as cheap fillers in foods, that are aren’t readily broken down and utilised by the body.
This idea continued into the 80’s with low fat being promoted for weight loss – think Rosemary Connolly. Because each gram of fat contains around 9 calories, compared with carbs at around 4 calories, it was a natural conclusion that calorie for calorie, a low carb diet would mean we would be slimmer.
But the problem is, since the 1980’s obesity is continuing to rise despite the supermarkets being flooded with low fat products. What hasn’t been taken into account is the effect on insulin that carbohydrates have compared to fat, and this is instrumental in weight gain. Any excess of carbohydrates or fat will be stored as fat, but the process of fixing fat in the cells is driven by insulin which is released in response to carbohydrate and sugar, not fat. If we opt for low fat when trying to lose weight you increase your carbohydrates which can upset blood sugar causing fatigue, cravings and low mood. Because of the low fat regime, our diets are high in carbohydrate, replacing much needed protein and fats which impact on our greatly on our mood and depression.
The other factor as far as ‘functional foods’ are concerned is that when the fat is removed, the taste and satisfaction is diminished forcing manufacturers to compensate with higher levels of sugar or salt – not healthy!
Most people know that essential fats, especially the omega 3 fats found in oily fish are good for us. But what about saturated fat found in dairy products and meat, should we eat these? Our ancestors who ate full fat dairy and fatty meat weren’t obese. In my opinion, heart disease has been more affected by increased smoking, increased sugar and alcohol, increased stress and a reduction of exercise, rather than levels of fat. Do we need saturated fat?
- Saturated fat is a component of our cells and helps keep them firm
- It transports the fat soluble vitamins, A, D, E and K which are vital for skin, immunity, fertility and bones
- The addition of saturated fat to the diet reduces the levels of a substance called lipoprotein that correlates strongly with risk for heart disease
- Saturated fat has been shown to protect the liver from the toxins such as alcohol and medications
- Saturated fats found in butter and coconut oil play key roles in immune health. Loss of sufficient saturated fatty acids in the white blood cells hampers their ability to recognize and destroy foreign invaders, such as viruses, bacteria, and fungi
- Research shows that although most saturated fatty acids increase LDL (“bad”) cholesterol, they also raise HDL (“good”) cholesterol just as much, if not more. And this lowers your risk of heart disease.
What about weight loss? Professor Kerry J Stewart from the Johns Hopkins University School of Medicine studied participants on a low carb and a low fat diet. Those on the low-carb diet lost a lot more weight than those on the low-fat diet – about 29 lbs v 19 lbs. They were also tested for a measure of health in the cardiovascular system. Professor Stewart quotes “Our study demonstrated that the amount of improvement in the arterial vessels was directly linked to how much central, or belly fat, the individuals lost, regardless of which diet they were on. This is important since there have been concerns that a low-carb diet, which means eating more fat, may have a harmful effect on cardiovascular health. These results showed no harmful effects from the low-carb diet.”
We need to shake off the idea of fat is bad, eating fat is more satisfying, keeps us going longer and helps alleviate depression. This doesn’t mean that you can gorge on cream, but go back to enjoying butter, full fat milk, Greek yoghurt, red meat and some crackling in moderation. There is no need to strive to keep fat out of your diet.