In recent months there has been a paradigm shift in public health reporting, with fat breathing a sigh of relief as sugar faces a rapid rise to public enemy number 1. However, as campaigners take aim at fizzy drinks and fruit juice are we still focussing on the wrong macronutrient?
The global obesity epidemic is growing, with 34% of adults now classified as overweight or obese globally.
Tragically even our beloved pets haven’t escaped the obesity, with vets classing 45% of pets as obese. Despite some blaming pet food manufacturers, it is clear that the choice we make, for ourselves and our pets, are causing massive health problems.
Similar to many other species, when given a choice of diets humans prioritize protein, and are willing to overeat carbohydrates and fat to reach this target. This is likely because the costs of not eating enough protein are large in terms of growth and reproduction compared to the costs of eating too much of other macronutrients. There is now considerable evidence suggesting that human prioritize protein towards a target intake. Ancestrally this hasn’t been a problem, but with modern diets the situation changes. With the advent of modern agriculture carbohydrate and fat became much cheaper as a way of bulking out food, resulting in a fall in the percentage of diet that comes from protein from 14% in 1961 to 12.5% in 2010. This results in the need to eat more carbohydrates and fat to reach the protein target, which can lead to obesity. There is evidence that it is protein intake that is the driver of total energy intake.
It is important to note that this isn’t about letting fat and carbohydrates off the hook, it’s about considering obesity in terms of a balance of fat, carbohydrates and proteins. It is also important that a dietary shift aligned to this theory doesn’t require a large increase in protein production, which is limited in many places, rather it requires choices based on the balance of nutrients.
Many of the recent recommendations of dietary change are likely to have positive effects. The warnings of the dangers of low fat options, which often simply swap fat with sugar, are welcome, as are aims to reduce the proportion of daily intake that comes from sugar. It is the portraying as fat or sugar as the key villain against obesity that sends the wrong message and can lead to ineffective interventions.
With the massive choice available in a modern diet it seems maladaptive that humans aren’t able to choose a diet that enables the protein appetite to be satisfied without the need to overeat fat and carbs. The answer here may lie with sugar, with humans developing a sweet tooth which may have been adaptive when sugar was a rare component of diet, but is now causing massive problems.
Appetite is a powerful curse, and simple interventions involving eating less are less likely to succeed if they are up against it. Fulfilling this protein appetite without overeating is an immense challenge against the willpower of humanity, given the breadth of dietary options available, but knowledge of how this system works can alleviate the obesity epidemic. Obesity and overweightness costs the NHS alone over £4 billion annually, and full use should be made of science that can provide practical and effective solutions.
A legitimate response to this hypothesis is the fact that a lot of people get obese eating high protein foods, such as burgers and fried chicken. This is where the importance of a balance of macronutrients becomes important.
As the cost and prevalence of obesity continues to grow, we cannot continue to ignore the importance of protein targets in the battle against obesity. The science examining this issue is hidden from public view and poorly reported, with even keynote reports by global organisations failing to recognise the potential importance of these findings. As the WHO responds to recent developments by changing their guidelines on sugar intake, battled by the powerful sugar lobby, it is important that protein is brought to the fore, so the root causes of obesity can be tackled. A switch in focus to reaching target protein intake without massively overeating carbohydrate and fat could prove more fruitful in the ongoing war against obesity.
Next time you are browsing the supermarket for a healthy snack, look at the ratio of protein to carbohydrate as well as the fat and sugar content.
Sugar is being massively blamed http://www.theguardian.com/society/2014/jan/09/obesity-campaign-cut-sugar-processed-foods
Nearly half of pets are now obese in UK http://www.telegraph.co.uk/lifestyle/pets/10747181/Nearly-half-of-dogs-are-now-obese-say-vets.html
Pet obesity report http://www.pfma.org.uk/_assets/docs/PFMA_WhitePaper_2014.pdf
UK obesity: 24% men 26% women http://www.nhs.uk/news/2013/02February/Pages/Latest-obesity-stats-for-England-are-alarming-reading.aspx
Biggest increased occurring in developing world http://www.bbc.co.uk/news/health-25576400
Future diets report http://www.odi.org.uk/future-diets
Follows the prevailing message in talking about the increase in sugar content, but not mention of protein http://visual.ly/future-diets-sugar-consumption-rising