Science, Evolutionary Biology, And Simple Economics Say Bloomberg’s Soda Ban Is Right

Author: Jared Bernstein Source: Business Insider

A few weeks ago, I wrote about the political economy of the obesity epidemic. Here, from a great oped in yesterday’s NYT, is the evolutionary science behind both the problem and the solution.

Here’s the argument (though I strongly urge you to read the extremely well-crafted piece):

Since sugar is a basic form of energy in food, a sweet tooth was adaptive in ancient times, when food was limited. However, excessive sugar in the bloodstream is toxic, so our bodies also evolved to rapidly convert digested sugar in the bloodstream into fat. Our hunter-gatherer ancestors needed plenty of fat — more than other primates — to be active during periods of food scarcity and still pay for large, expensive brains and costly reproductive strategies…

Simply put, humans evolved to crave sugar, store it and then use it. For millions of years, our cravings and digestive systems were exquisitely balanced because sugar was rare. Apart from honey, most of the foods our hunter-gatherer ancestors ate were no sweeter than a carrot…it wasn’t until very recently that technology made pure sugar bountiful.*

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Comments

Post: July 11 2012 9:29 pm By: f

Adaptive sweet tooth for the purpose of maximizing energy intake doesn’t clearly make evolutionary sense. Tubers, which humans did eat, have greater energy yields, yet plain tubers are much less attractive than plain fruit (the ancient source of sugar).

Plain sugar does NOT turn into fat within the body, except under extreme (irrelevant) circumstances. Consult the scientific literature.

Nor is it obvious that some human ancestors did not consume abundant amounts of sugar via fruit. Monkeys exist which subsist primarily on fruit. If monkeys can do it, humans probably could and did too.

Sugar is not clearly a cause of obesity. Sucrose raises the metabolic rate, meaning you burn more calories in shorter time. Mice studies have shown mice capable of eating 50% more calories on a high-sugar diet, with no increase in fat mass. Some human studies have shown greater weight loss on moderate-sugar diets rather than low-sugar diets.

High-fructose corn syrup (as seen in sodas) is not completely comparable to regular sucrose. HFCS has 4x more calories per gram than sugar, in the form of non-digestible polysaccharides. Humans don’t absorb this, but ubiquitous microbes in the human gut do and this likely is a factor in why HFCS is harmful while plain sucrose is not.

The science is not obvious. Some scientists and bureaucrats alike have an interest in making controversy and appearing as if they care and are ‘taking action’.