A few weeks ago, I went to Leura to attend a 3 hour seminar on obesity, held by Metagenics. It was a great turn out from practitioners from Sydney, Canberra as well as the Blue Mountains and Central West.
In Australia, it is estimated that by the year 2025, there will be more obese
(BMI >30) people than people in the healthy weight range (BMI 20-25). Currently 63% of Australians are overweight or obese.
Why is this so important? Obesity is a medical issue in terms of the potential health implications. The more fat mass a person carries the greater risk of chronic disease:
- Cardiovascular disease
- Sleep apnoea
- Mood disorders
- Neurological diseases
Even modest amounts of weight loss (5-10% reduction) leads to dramatic improvements in health. The Diabetes Prevention Program showed that losing 5.5% of body weight over 2.8 years, decreases the risk of getting diabetes (from a pre-diabetic situation) by 48%. (1)
Obesity relates to our brains – they drive what we eat. We are hardwired to seek out more calories and remain less active, so we have ample supplies for the lean times. But in 2018 with food available 24/7 the lean times don’t come.
Body weight regulation is under UNCONSCIOUS homeostatic control – similar to blood pressure, blood sugar and pH regulation. The body weight our body likes to maintain is called the “body weight set point”. There is a 2-6kg fluctuation around this point. (2)
Our body weight set point is developed around the age of 20y, around 24y in some males. This body weight set point goes up in our 50s and as we then get older, this starts to drop. If there is obesity in childhood, the body weight set point will be set higher at an earlier stage.
Our brains control the energy we use. For example, in a group of obese people who had 20% weight loss, they were inclined NOT to move MORE than obese people who had lost 10%.
So, the gut-brain connection rears up again – in animal studies, inflammation in the brain (in particular the hypothalamus) precedes obesity. What drives inflammation? A high fat and high sugar diet. Eating food triggers dopamine release, a neurotransmitter, which activates reward, motivation and learning centres in the brain. The more calorie dense a food is, the more dopamine is released. (3)
Studies show that obese people demonstrate higher reward centre activation in the brain compared with lean controls. (4)
What are some of the real causes of obesity in 2018?
- We are eating more than we have historically – calorie intake is 425 kcal/day higher
- The body weight set point is reset so there is a 20% increase in energy intake (2)
So, what can we do to lower the set-point?
- Have a diet with low to moderate palatability (tastiness)
- Eat adequate protein
- Restrict fat OR carbohydrate
- Have diet breaks (time off restricted eating, to prevent metabolic adaption and give a psychological boost)
- Ensure adequate good quality sleep
- Maintain good levels of physical activity
Having a buddy when focusing on weight loss has been shown to be very beneficial for accountability, psychological support and better outcomes.
Watch out with the upcoming holiday season….much of weight gained through the year happens during the smallest window. Research shows that annually 52% of weight gain occurs over the holiday season, which is only 12% of the year. Lots of hyper-palatable (very tasty) food is consumed/over-consumed, which has been found to drive up the set-point. (5)
- Diabetes Prevention Program Outcomes Study. Lancet. 2009 14;374:1677-86
- Obesity Pathogenesis: An Endocrine Society Scientific Statement. Endocrine Rev. 2017 1;38:267-296
- The gut-brain dopamine axis: a regulatory system for caloric intake. Physiol Behav 2012 6;106:394-9
- Widespread reward-system activation in obese women in response to pictures of high-calorie foods. Neuroimage 2008 41:636-47
- Defence of body weight depends on dietary composition and palatability in rats with diet-induced obesity. Am J Physiol Regul Integr Comp Physiol. 2002 282:R46-54