For a number of years now I've been of the belief that at the core of consuming excess calories is inadequate protein and essential nutrients. Basically, those who are obese are in a state of "overconsumptive malnutrition," their hunger driven not by gluttony, but unfulfilled nutrient requirements.
To say hard evidence for this is sparse is an understatment. While there is data which points to nutrient deficiency and data pointing to protein inadequacy, there isn't much out there specifically investigating calorie intake based on nutrient adequacy. Today the Sydney Morning Herald reports findings from researchers at the University of Sydney in Skinniness gene imperils survival of the fattest who studied crickets, cockroaches, rats, minks and even humans in an effort to understand how protein requirements drive food consumption, for some, but not all, humans.
The lead researcher, Dr. Stephen Simpson, found that crickets are driven across the landscape, consuming crop after crop, because they have a fixed protein requirement. To meet that requirement, these pests will cannibalize each other along the way, so the frantic pace to keep moving is a survival mechanism, "stop and you get eaten."
To understand how protein requirements may play in human eating habits, the researchers "incarcerated 10 people in a chalet for six day," to monitor their eating.
For the first two days they could eat what they wanted from a buffet. For the next two days, one group was restricted to high-protein foods, such as chicken and meat, the other to fatty, sugary, low-protein foods, such as croissants.
The first group consumed exactly the same amount of protein as on the first two days. "The second group went way off the mark and just kept on eating until eventually, through their over-consumption of carbohydrate-rich foods, they managed to fill their protein intake."
As Dr. Simpson noted, "A slight shift in the diet towards a lower proportion of protein can have catastrophic effects, your body will stop you eating when you reach the right amount."
In their caterpillar research, they found that the disadvantages of obesity can change the course of evolution in a species. In one experiment, they confined hundreds of caterprillars to a high-carbohydrate diet. Over generations of obesity, the caterpillars slowly became immune to obesity in a high-carbohydrate world; no longer laying the excess carbohydrate down as fat. They also were left with an increased risk of starvation were the world to change and carbohydrates became scarce.
Their cousins, confined to a low-carbohydrate diet showed similar adaptions to their diet and evolved to the opposite, prone to obesity in a carbohydrate-rich environment, depositing excess as body fat when their environment changed.
As Dr. Simpson said "But were they, like we humans, to suddenly find themselves in a world where high-energy foods were abundant, they would be super-prone to becoming obese. This raises the possibility that our diet could significantly influence our genetic evolution over the next few generations."
In Let's Blame Evolution for our Obesity Epidemic, I wrote "it might just be evolution that stops the obesity epidemic for us as we continue our folly with low-fat, fortified, carbohydrate-rich diet recommendations."
I based that on the health of our youth today, where children are already symtomatic with "type II diabetes, atheroclerosis, dyslipidemia, hypertention and cardiovascular disease already present in an alarming number of our youth. Add to that the rising trend of "precocious puberty" where children are maturing much earlier than previous generations."
Survival of the species happens through those endowed with characteristics which improve chances of survival and reproduction, through those who do reproduce and propagate off-spring with heritable characteristics that affect their survival and reproductive success. After millions of years and thousands of generations, today we have inherited a set of characteristics that require, among other things, specific nutrients if we are to reproduce and survive. In a very short time span, we've modified our diet radically from that of our ancestors. If evolution is playing here, it's not playing very nicely in the sandbox of our genes. But, evolution isn't making us fat, we're doing that because we are not "playing within the bounds" of our genetic requirements, especially the requirements for nutrients that optimize reproduction and survival.
The alarming number of children today that are already showing signs of chronic disease and characteristics of infertility is alarming. The stark and painful reality is that this may be evolution exerting influence to limit reproduction potential of those unable to consume a nutritionally complete diet. Without an appropriate and adequate diet, the youngest among us are being afflicted earlier and earlier with chronic disease, characteristics of infertility, and a potentially shorter life-span to be lived battling chronic illness.
What I wrote sounds eerily familiar to what the article stated "This would occur if those with a propensity for stacking on the kilograms cannot reproduce or they have less healthy children, while the lean survive to pass on their skinniness genes.
Signs of this are emerging. Children are developing type 2 diabetes. Overweight women are having difficulty conceiving. "For the first time we are seeing obesity-related health problems affecting significant numbers of reproductive aged and pre-reproductive aged humans," Simpson says.