Not that I am turning into a nutrition junkie or anything but I am reading a fascinating book by Dr Robert Lustig called Fat Chance. He is a paediatric endocrinologist which means he has spent many years trying to understand the reasons for infant and childhood obesity, and while he is supportive of the theory ‘eat less, exercise more’ he is on a mission to tell the world there is much more to learn from the biochemistry of fuelling up with food.
Hormones control our eating behaviour. Most digested nutrients from the small intestine go straight to the liver for processing but what the liver can’t immediately take up circulates in the blood. The pancreas is then deployed to secrete insulin which directs excess glucose to be stored by the liver, amino acids by the muscles and lipids by the fat cells. The more insulin activity, the more fat is being stored. Of course when the process is reversed and insulin levels drop then fat cells shrink as their energy supply is used. This whole energy balance is managed by the brain when it receives signals from another hormone secreted by the fat cells called leptin which tells it there is enough in the energy reserves.
Cutting a long and interesting story short, the villain of the modern diet is sugar in its multiple forms, not the glucose part which is an essential nutrient but the fructose part which you find in all sources of sweetness: honey, agave nectar, dried fruits and fresh. Too much of it interferes with the leptin signalling so that misinformation is transmitted through the body leading to all sorts of short and long term health issues.
I am only halfway through the book but it reaffirms my instinct to be working with a wide variety of fresh and unprocessed ingredients since most processed foods are riddled with sugars, especially the low fat kinds (thankfully we are not a soda household because they are absolutely toxic). Where there needs to be caution in my diet is not so much the odd craving for milky chocolate but regular fruit intake (fresh and dried) especially when it is stripped of its natural fibre. Dare I say it, but the whole smoothie/juicing trend is not as healthy as it sounds. Based on Lustig’s presentation of the sugar facts, if you’re thirsty drink water, if you’re hungry and thinking of your “5 a day” then chew the whole fruit and nothing but the fruit. Make that fruit smoothie or juice a treat and not a daily fix.