Carbs, Not Calories

In the latest Rundown, connected fitness gets climbing, scientists identify a muscle strength gene activated by exercise and a new paper claims that carbs not calories lead to obesity.

The Rundown

Connected Climb. With CLMBR, vertical climbing meets the connected fitness space. Unlike traditional climbers that have a center pole, this version has an open frame, two pole design, which allows for an unobstructed view of the 21.5” HD touchscreen. The handles have multiple grip positions and can be adjusted to the user’s height and the machine has wheels for easy placement. Classes are available for a monthly membership fee.

Muscle Gene, Activate! Exercise strengthens muscle but exactly how it does this is complex so researchers at the Universities of Melbourne and Copenhagen decided to untangle the mystery. Their study identified the molecular similarities and differences between various types of exercise in human muscle biopsies by analyzing proteins and how they changed within cells.

Lead author Dr. Benjamin Parker explains it this way, “To identify how genes and proteins are activated during and after different exercises, we performed an analysis of human skeletal muscle from a cross-over intervention of endurance, sprint and resistance exercise.”

The researchers then compared signaling responses between different types of exercises in the same person, meaning they could monitor how an individual responded to the exercises directly in their muscles.

They could also identify genes and proteins that consistently changed across all individuals and all types of exercise, which lead to the discovery of a gene called C18ORF25.

When they engineered mice to lack this gene, the animals developed smaller skeletal muscle fibers. This translates to weaker muscles and reduced exercise performance. When the gene activity was increased, the animals’ muscles became stronger, without necessarily becoming bigger.

The researchers hope that by identifying the gene and understanding how different types of exercise draw out health effects at a molecular level, it will be possible to manage muscle atrophy, healthy aging, sports science and even livestock and meat production.

Carbs, Not Calories. In a new paper published in the European Journal of Clinical Nutrition, a group of researchers, physicians and public health experts argue that overeating isn’t the primary cause of obesity. Rather, the process of gaining weight causes us to overeat.

The carbohydrate-insulin model of obesity theorizes that processed, fast-digesting carbs like white bread, white rice, potato products, prepared breakfast cereals and sugary foods, raise insulin levels too high and produce other hormonal changes that program our bodies to store extra fat.

According to the model, when calories are stored in fat tissue, there aren’t enough left in the blood to satisfy the body’s energy needs so our brains make us feel hungrier sooner after eating to make up for the stored calories. If we try to ignore hunger and restrict calories, our bodies conserve energy by slowing metabolism.

If this theory is correct, cutting back on calories doesn’t work over the long term because it doesn’t address the underlying problem of storing excessive fat driven by hormones and other biological influences. The researchers argue that the focus should be on reducing the surge of blood glucose and insulin after meals with a higher-fat diet low in processed carbs.

The authors of the paper admit that despite other scholarly work supporting the carbohydrate-insulin model the idea that it’s more correct than calorie counting is difficult to prove with the current state of research.

Yet, they argue that variations of the calorie counting approach keep failing and obesity rates keep rising so it’s critical to consider new ways of solving the problem. “Overeating is a symptom,” they say, “not a cause.”

Replay

This week’s vintage moment in fitness culture is brought to you by Mohammad Ali jogging alongside Queen Elizabeth II’s horses in Knightsbridge, London, 1966. Photo credit: A.P. Images.