3 There is some evidence that the leptin secreted by the fat cell may also be responsible for the recruitment of cellular police, but the result is the same: inflammation around the fat cells and inflammation spreading throughout the body.
4 By down-regulating tyrosine kinase activity in the insulin receptor.
5 Insulin resistance and obesity go hand in hand – 90 per cent of incidences of Type 2 diabetes (caused by insulin resistance) are overweight or obese.
SIX: The Last Resort
1 GLP stands for ‘glucagon-like peptide’. Just like PYY, it is released into the bloodstream by the small bowel after eating. It travels to the hypothalamus and causes the satiety feeling that is the signal to stop eating. As well as producing satiety, it has a second effect of making insulin much more efficient. This is the reason Type 2 diabetes often goes into complete remission immediately after a bypass (or sleeve) operation.
SEVEN: The Master Chef
1 ‘Obesogenic’ means ‘causing obesity’.
2 Mitochondria are like little furnaces within our cells, constantly generating heat and power. Our metabolism, that is the amount of energy that we can use, is dependent on these furnaces.
3 Power is measured in watts, which we usually relate to electrical appliances, but it applies to all living and moving things. It is the amount of energy used per second. The power might come from electricity in the case of a washing machine, or a petrol engine in the case of a car, or food (then ATP) in the case of animals. To get things into perspective, 1 joule of energy is the amount used to lift an apple out of a 1-metre-deep barrel; 1 watt is the power required to lift that apple 1 metre in 1 second. To lift ten apples (or about 1kg) up 1 metre in 1 second takes 10 watts of power.
4 Atheroma is the ‘furring and narrowing’ of blood vessels that affects most adults living in the West. It can lead to heart attacks, strokes, kidney failure and many other Western diseases.
5 Until the twentieth century sugar was transported and sold in the form of a ‘sugar loaf’ – a large conical-shaped lump of congealed sugar. The sugar loaf was prized and made to last for a long time: special pliers were needed to break pieces of sugar off the solid loaves.
NINE: The Omega Code
1 Of note is that one of the most exciting and effective drug treatments for obesity appeared ten years ago. This was a drug called Rimonobant and it blocked the CB1 (cannabis) receptors in the brain – the same receptors stimulated by the endocannabinoids originating from omega-6s. Many of my patients taking the drug reported great weight loss. However, Rimonobant was taken off the market after only one year with reports that it could lead to psychosis and even suicide.
TEN: The Sugar Roller Coaster
1 Insulin is also produced after eating protein. However, at the same time as insulin is released, protein also stimulates a hormone called glucagon. Glucagon has the opposite action to insulin, so in effect protein remains insulin-neutral.
2 Unless we are in starvation mode, in which case our cells break down fat and produce a glucose substitute in the blood called ketone bodies.
3 High triglyceride levels are implicated in the risk of heart disease. High sugar intake causes the production of triglycerides. It is increasingly accepted now that sugar in the diet, and not natural saturated fat, is the true heart disease risk (see Appendix 1).
4 This process that takes place in the liver is known as the microsomal ethanol oxidizing system.
ELEVEN: The French Paradox
1 Nutritionism, a term used by Michael Pollan, an American journalist, in his book In Defence of Food: An Eater’s Manifesto (2008) to describe the ideology of scientific food reductionism, attempts to understand food by breaking it down into its constituent parts – carbohydrates, fats, vitamins, minerals etc. – and then examines those constituents and tries to work out what is good and what is bad. Nutritionism ignores food culture and suggests that nutritional science can give us the perfect eating advice. Unfortunately, today most of the advice is counter-productive to human health.
THIRTEEN: The Fat of the Land
1 Some people describe putting on weight when they meet and move in with their true love. This life-change triggers the same biological nesting response as marriage – your set-point doesn’t need a marriage certificate!
2 This applies to diurnal animals – those that are awake and active in the daytime.
3 Imagine the difference in obesity genes between a Labrador, which has a common genetic mutation that causes a susceptibility to obesity, and a greyhound. Give them both processed dog food (with the omega-3 taken out) and the Labrador will invariably become overweight, but the greyhound can eat as much as it likes and it will not put on excessive weight. These differences in genetic sensitivities to obesity exist just as dramatically in humans.
FIFTEEN: Eat More, Rest More
1 Do not be scared of cholesterol or saturated fats – we have discussed the flawed research in this area at length in chapter 8. Natural saturated fats (not artificial polyunsaturated vegetable oils) do not make you fat and have less risk than sugar for heart disease. Replacement of these fats in our diet by oils and sugar in the 1980s precipitated the current obesity epidemic. There is an additional scientific section on cholesterol in Appendix 1 of this book.
2 Ofcom Media Nations 2019 report for the UK, published 7 August 2019.
SIXTEEN: Your Personal Blue Zone
1 There has been only one single study suggesting that vegetable oils lower the risk of heart disease: this study is often quoted on food labels – but scores of further studies have failed to find a protective effect.
2 The olive oil should be bought in a tin or, if in a glass bottle, it should be stored in a dark cupboard as sunlight degrades the healthy antioxidants in the oil.
3 Metabolic adaptation is the decrease or increase in our metabolism in response to dieting or over-eating – as discussed in chapters 1 and 3 in Part One.
4 This took into account the relative sizes of the Hadza hunters and city dwellers. In actual fact, the hunter-gatherers used up less energy than the city dwellers because they were smaller.
EPILOGUE: Why Do We Eat Too Much?
1 The amount spent annually on advertising products in the food industry is one hundred times more than is spent by the government on healthy eating campaigns.
Why We Eat (Too Much) Page 37