Tag Archives: calories

Exenatide and tapeworms, Op. 116

The great Dr. Schoeller can polish a turd like no other.  Dale Schoeller’s claim to fame is his extensive work on one of the best ways to measure total energy expenditure in free-living individuals: doubly-labeled water.  In doubly-labeled water, subjects drink stable isotope-labeled water; instead of hydrogen + oxygen = H20, the stable isotope-labeled water is deuterium + oxygen-18 = D218O.  Deuterium is excreted just like hydrogen, in water as urine & sweat.  Oxygen-18 is excreted just like oxygen, in water and carbon dioxide.  So the subjects lose deuterium & oxygen-18 in water at equal rates, but only oxygen-18 in carbon dioxide; so this technique basically measures carbon dioxide production, which is proportional to energy expenditure.  Clever. 

Being that Schoeller practically invented the technique, his interpretation of these total energy expenditure data are not flawed, but that’s not where he went astray.

Alterations in energy balance following exenatide administration (Bradley et al., 2012)

Continue reading

The Laws of Energy Balance FTW!

Weight loss maintenance is not determined by calorie intake… or physical activity… but by The Laws of Energy Balance FTW!!!

Odd, the sensation I felt when reading this news release (gloating?).  As reported at a meeting of the Obesity Society, results from the Utah Obesity Study of gastric bypass patients 2 and 6 years after surgery.  By the 2 year mark, they lost over 100 pounds, or 36% of their starting weight (went from 296 to 189 pounds).  Energy expenditure declined from 2201 to 1736 kcal/day.  Food intake went from 2085 to 1638 kcal/day.  (Hint: it’s no coincidence that energy expenditure and food intake declined to the exact same degree.)  Physical activity and fitness levels increased.

By the 6 year mark, they still weighed 29% less than their starting weight.  N.B. that’s an amazing level of success, it’s virtually unheard of in diet intervention studies.  +1 for gastric bypass; -1 for nutrition.

Here’s what piqued my interest: during the gradual increase from 189 pounds to 210 pounds, which occurred between years 2 and 6 post-surgery, the most significant factor associated with weight regain was not calorie intake or physical activity… it was metabolic rate.  This represents another fail for “eat less move more,” and a win for the Laws of Energy Balance.

So what’s this got to do with The poor, misunderstood calorie?

what we know about metabolic rate:

1)      It’s invisible.

2)      Fructose vs. The Laws of Energy Balance (circa December, 2011): sugar-sweetened beverages can cause fat gain, not by providing excess calories, but by reducing metabolic rate.

3)      Holiday feasts, the freshman 15, and damage control (circa January 2012): overeating a high protein diet causes less fat gain than overeating anything else because it increases metabolic rate.

4)      Missing: 300 kilocalories (circa July 2012):  after losing weight, subjects assigned to the low carb diet maintained a higher metabolic rate than those on an isocaloric low fat diet.

“Eat less move more” is not the answer.  But eating less sugar, more protein, and fewer carbs might be.  Nutrition matters.

calories proper

A historical argument against caloric equality

80 years later, a calorie still isn’t a calorie.

Exhibit A.

The treatment of obesity   (Lyon and Dunlop, 1932)

As early as 1932, Lyon and Dunlop recognized that the calories from as little as one slice of bread every day could result in pounds of fat mass gained every year.  For whatever reason, this doesn’t happen to lean people; so they decided to study the effect of different diets on obese subjects in a metabolic ward at the Royal Infirmary.

Their idea of a “diet:” If they could only see how much times have changed!  (this is a hotly debated topic.)

Lyon and Dunlop first tested weight loss vs. total calorie intake.  The diet was roughly 40% carbs, 24% protein, and 36% fat.  Not surprisingly, people fed 800 kcal/d lost more weight than those given 1,000 or 1,200 kcal/d (200 vs. 172 vs. 157 grams of body weight lost per day over the period of 7 – 10 days), confirming that the less you eat, the more weight you lose (duh).  A calorie is a calorie after all, right? …

Continue reading