Tuesday, February 28, 2012

Palatability, Satiety and Calorie Intake

WHS reader Paul Hagerty recently sent me a very interesting paper titled "A Satiety Index of Common Foods", by Dr. SHA Holt and colleagues (1).  This paper quantified how full we feel after eating specific foods.  I've been aware of it for a while, but hadn't read it until recently.  They fed volunteers a variety of commonly eaten foods, each in a 240 calorie portion, and measured how full each food made them feel, and how much they ate at a subsequent meal.  Using the results, they calculated a "satiety index", which represents the fullness per calorie of each food, normalized to white bread (white bread arbitrarily set to SI = 100).  So for example, popcorn has a satiety index of 154, meaning it's more filling than white bread per calorie. 

One of the most interesting aspects of the paper is that the investigators measured a variety of food properties (energy density, fat, starch, sugar, fiber, water content, palatability), and then determined which of them explained the SI values most completely.

Monday, February 27, 2012

Soda-Free Sunday

Last Thursday, I received a message from a gentleman named Dorsol Plants about a public health campaign here in King County called Soda Free Sunday.  They're asking people to visit www.sodafreesundays.com and make a pledge to go soda-free for one day per week. 

Drinking sugar-sweetened beverages (SSBs), including soda, is one of the worst things you can do for your health.  SSB consumption is probably one of the major contributors to the modern epidemics of obesity and metabolic dysfunction.

I imagine that most WHS readers don't drink SSBs very often if at all, but I'm sure some do.  Whether you want to try drinking fewer SSBs, or just re-affirm an ongoing commitment to avoid them, I encourage you to visit www.sodafreesundays.com and make the pledge.  You can do so even if you're not a resident of King county.

Wednesday, February 22, 2012

Is Sugar Fattening?

Buckle your seat belts, ladies and gentlemen-- we're going on a long ride through the scientific literature on sugar and body fatness.  Some of the evidence will be surprising and challenging for many of you, as it was for me, but ultimately it paints a coherent and actionable picture.

Saturday, February 18, 2012

By 2606, the US Diet will be 100 Percent Sugar

The US diet has changed dramatically in the last 200 years.  Many of these changes stem from a single factor: the industrialization and commercialization of the American food system.  We've outsourced most of our food preparation, placing it into the hands of professionals whose interests aren't always well aligned with ours.

It's hard to appreciate just how much things have changed, because none of us were alive 200 years ago.  To help illustrate some of these changes, I've been collecting statistics on US diet trends.  Since sugar is the most refined food we eat in quantity, and it's a good marker of processed food consumption, naturally I wanted to get my hands on sugar intake statistics-- but solid numbers going back to the early 19th century are hard to come by!  Of all the diet-related books I've read, I've never seen a graph of year-by-year sugar intake going back more than 100 years.

A gentleman by the name of Jeremy Landen and I eventually tracked down some outstanding statistics from old US Department of Commerce reports and the USDA: continuous yearly sweetener sales from 1822 to 2005, which have appeared in two of my talks but I have never seen graphed anywhere else*.  These numbers represent added sweeteners such as cane sugar, high-fructose corn syrup and maple syrup, but not naturally occurring sugars in fruit and vegetables.  Behold:

Saturday, February 11, 2012

Cigarette Smoking-- Another Factor in the Obesity Epidemic

Obesity rates in the US have more than doubled in the last 30 years, and rates of childhood obesity and extreme adult obesity have tripled.  One third of US adults are considered obese, and another third overweight.  This is the "obesity epidemic".

The obesity epidemic has coincided with significant changes in the US diet, which are clearly involved.  However, there's another probable contributor that's often overlooked: declining smoking rates.  

Here's a graph I prepared of cigarette consumption over the last century in the US (1):

Monday, February 6, 2012

My TEDx Talk, "The American Diet: a Historical Perspective"

On October 21st, I spoke at the Harvard Food Law Society's TEDx conference, Forum on Food Policy.  The conference kicked off with three talks on nutrition, by Drs. Walter Willett, David Ludwig and myself.  My talk is only 17 minutes long as per TED format, but it's packed with research on both quantitative and qualitative changes in the US diet over the last two centuries.  It contains surprises for almost anyone, and I can guarantee you've never learned this much about the history of the US diet in 17 minutes.  The talk was titled "The American Diet: a Historical Perspective"; you can access it by following that link.

Saturday, February 4, 2012

An Interview with Dr. C. Vicky Beer, Paleo-friendly MD

As I was preparing my recent article on the Paleo diet (1), I interviewed a local Paleo-friendly MD named C. Vicky Beer.  I was only able to include a snippet of the interview in the article, but I thought WHS readers would be interested to read the rest of the interview with Dr. Beer: