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Rutabagas and Weight Loss

A connection between rutabagas and weight loss? Let’s get to the root of it.

I’ve judged a lot of science fairs in my life. I’ve seen innumerable baking soda volcanoes, vitamin C analyses and models of the solar system. Usually, the judges’ task is over once the winners are announced, but on one memorable occasion, the event was followed by an assembly where a game of “Challenge the Judge” was played. Students were asked to name a single object that the judges were then to incorporate into a scientifically meaningful sentence. A student panel would then determine a winner based on the ingenuity of the response.

There were half a dozen of us on the stage and I was in the middle. The first judge, a physicist, was challenged with the word “flag” and quickly came up with “the American flag planted on the moon had to be supported by a metal rod because there is no air on the moon and it is the movement of air that makes a flag wave.” Next was a dentist who was to use the term “angel.” She commented that she wasn’t sure if angel was an object, but nevertheless cleverly offered, “you have to wear gloves when handling Angel’s Trumpet because the plant contains atropine that can be toxic.”

Now it was my turn. “Rutabaga” was the chosen student’s submission. I was in luck because had I been challenged with this the week before, I would have come up empty. I may have been able to mutter something about it being a vegetable, but that would have been it. As luck would have it, just a couple of days earlier I had been researching an article on weight loss diets and came across the “Minnesota Starvation Experiment,” a fascinating study carried out at the University of Minnesota in 1944 by Dr. Ancel Keys. The legendary physiologist had already achieved fame as the designer of the army’s “K-rations” and would later go on to become a household name by linking the consumption of saturated fat with heart disease and championing the “Mediterranean Diet.”

Starvation and war are often bedfellows. Keys knew that famine was rampant in war-torn Europe and that once hostilities ended doctors would have to deal with health issues linked with undernourishment. However, there was very little information available about the physiological effects of starvation and the best ways to reintroduce food once it became available. Dr. Keys had an idea. He would enlist men who were willing to undergo near-starvation followed by different refeeding regimens. There was no problem finding volunteers given that the government allowed conscientious objectors to take part in the study as an alternative to military service. Eventually, 36 men were first put on a standardized diet of 3200 calories a day for three months during which their health status was carefully monitored. They lived together in a special facility, worked in a lab during the day, and were asked to walk an average of three miles a day.

After three months their food intake was cut to1570 calories a day while the same activity regimen was maintained. This semi-starvation diet was designed to include the foods that were typical of what would have been available in meagre amounts to the hungry of Europe during the war. The main ingredients were potatoes, cabbage, bread and yes, rutabagas! The latter caught my attention because I didn’t know very much about what they were. I quickly discovered that rutabagas are root vegetables in the turnip family and can be eaten boiled, baked, fried or raw.

On this “rutabaga diet” the men soon showed a decline in strength and energy. They became irritable, even funny movies at which they previously laughed had no appeal. Then there were the physiological effects. Heart size decreased and bowel movements became infrequent. Body temperature and heart rate were reduced. Mental acuity was impaired as the brain dialled back its energy use. Basic metabolic rate, the energy needed to maintain critical body functions, dropped from 1600 calories a day to 1000. This led to our current understanding of why people who go on calorie-reduced diets lose weight at first and then hit a plateau. The body compensates by curbing its energy use.

After a few months, the men’s ribs became visible and their bodies took on a skeleton-like appearance. Interestingly, they didn’t look upon themselves as too thin, they thought other people were too fat, a phenomenon that has also been noted in anorexics. At the end of the six-month period, the men had lost twenty-five percent of their body weight.

Then the refeeding began. Several regimens were tried with the conclusion that about 4000 calories a day were needed to rebuild strength. Neither vitamin nor protein supplements were of any help. Once the trial was over and the subjects were allowed to eat as much as they wished, they reported a sensation of hunger that could not be satisfied no matter how much they ate. And they ate a lot, often more than 5000 calories a day. Hunger finally abated when they had regained the weight they had lost.

The Minnesota experiment demonstrated that when we eat less, the body compensates by expending fewer calories. Also, as food intake decreases, irritability increases. So does a craving for food. It all makes for an unhappy situation which explains why 95% of people who want to shed those extra pounds are doomed to fail.

Keys went on to publish his research in a two-volume set entitled “The Biology of Human Starvation” in which he described for the first time the physiological and psychological effects of undernutrition and laid the foundation for our current understanding of weight control as well as eating disorders such as anorexia nervosa and bulimia.

Now back to my rutabagas. I blurted out something like “did you know that rutabagas played a key role in a 1944 study that demonstrated why 95% of dieters are doomed to fail?” A bit of a stretch, I must admit. In any case, I didn’t win. Who did? An engineer who was put to the test by a smug student with “civet”. Without flinching, he blurted out “I think the most delightful coffee in the world is made from beans that have been eaten and then defecated by the Asian civet cat.” An uncontested winner.


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