This weeks newsletter explores the recent research that suggests intermittent fasting may be good for us. I take a brief look at the medical evidence for this, then consider why, psychologically, it might be a good for us and why its good for the planet.
A bit of the science
Scientists are uncovering evidence that short periods of fasting, if properly controlled, could achieve a number of health benefits as well as potentially helping the overweight. Calorie restriction, eating well, but not much, is one of the few things that has been shown to extend life expectancy, at least in animals. For example mice put on a low-calorie, nutrient-rich diet live far longer. There is some evidence that the same is true in monkeys.
The world record for extending life expectancy in a mammal is held by a new type of mouse which can expect to live an extra 40%, equivalent to a human living to 110 or longer. It has been genetically engineered so its body produces very low levels of a growth hormone called IGF-1, high levels of which seem to lead to accelerated ageing and age-related diseases, while low levels are protective.
The IGF-1 hormone (insulin-like growth factor) is one of the drivers which keep our bodies in go-go mode, with cells driven to reproduce. This is fine when you are growing, but not so good later in life when age-damaged cells are replicated. There is now evidence suggesting that IGF-1 levels can be lowered by what you eat. The reason seems to be that when our bodies no longer have access to food they switch from “growth mode” to “repair mode” – rather than replicate damaged cells, we repair them. As levels of the IGF-1 hormone drop, a number of repair genes appear to get switched on according to ongoing research by Professor Valter Longo of the University of Southern California.
One area of current research into diet is Alternate Day fasting (ADF), involving eating what you want one day, then a very restricted diet (fewer than 600 calories) the next, and most surprisingly, it does not seem to matter that much what you eat on non-fast days. Dr Krista Varady of the University of Illinois at Chicago carried out an eight-week trial comparing two groups of overweight patients on ADF.
“If you were sticking to your fast days, then in terms of cardiovascular disease risk, it didn’t seem to matter if you were eating a high-fat or low-fat diet on your feed (non-fast) days,” she said.
An alternative to is an easier version, the so-called 5:2 diet. As the name implies you eat normally 5 days a week, then two days a week you eat 500 calories if you are a woman, or 600 calories, if you are a man. People who experienced this diet had improvements in blood markers, like IGF-1, glucose and cholesterol, as well reduced body fat statistics.
Although there are few long term studies on this sort of diet we can look at the experience of Norwegians during the second world war and Cubans after the fall of the Soviet Union (resulting in a reduction in the subsidy they received). Both populations experienced dramatic falls in their calorie intake and both experienced a huge improvement in their wellbeing statistics.
The psychology of hunger
All the major religions have fasting as a core element of their spiritual and wellbeing practices. One of the most interesting findings from the fasting research is that people seem to get smarter ie., they are quicker at solving problems and have improved recall. Why? Perhaps it’s because our brains are designed to work well when we strive. We get up in the morning to find food, acquire material possessions for warmth and protection and to look for sex to replicate our genes. We are also looking for meaning in life, looking to acquire knowledge and finding ways to help others.
So perhaps in the same way that we learn to restrict our diet we need to explore how to stay hungry in our career, in our love lives and how to stay open to new experiences, travel and friendship. Maybe people get old quickly when they become too satisfied in each area of their lives. In Positive Psychology we often measure people’s wellbeing levels by asking them how satisfied they are with their lives and we design interventions to help people to become more satisfied. Maybe we need to explore the power of restlessness and dissatisfaction to inspire growth and change?
The thing is, restlessness and dissatisfaction just don’t sound right. Somehow we need to cultivate a mindset of inner contentment whilst retaining an ambitious, engaged action orientated outlook – a difficult balancing act! In the yoga sutras the teaching is to keep your feet on the ground whilst striving to be as tall as you can. You work as hard as you can but you don’t overly attach to the fruits of your labours and outcomes.
A health planet
Approximately 100 million people in the US and 150 million in the EU are obese. Child deaths through malnutrition in 2011 were six million.
The food industries in the US and Europe are not controlled by evil people, but they are businessmen who want to sell us as much as possible at as high a margin as possible. To do this they have to sell highly processed food made from the cheapest ingredients. They take corn, (which is an ingredient in virtually every product we buy in a supermarket), add sugar, salt and fat, make it look attractive and sell it to us. This attractive looking stuff is served up in lovely packaging which builds our food cravings.
This kind of food robs our energy (because we eat too much of it) and robs the futures of the malnourished. Imagine the boost to global human energy if we distributed food fairly and ate foods that were not deconstructed and reconstructed into stuff so far removed from its original source (sunshine).
Lots of love,