Diets rich in fats and sugar, lack of physical activity, and genetic factors are linked to a higher risk of obesity but nutritionists have long debated the primary factor associated with weight gain. Now, a new study has found that fructose could be the root cause of obesity.
The study, led by researchers from the University of Colorado, has found that when fructose, a sugar found in fruits, table sugar and other foods, is metabolised, it lowers the active energy in the body which causes hunger and food intake.
In the study, lead author Richard Johnson introduces, the “fructose survival hypothesis”, which integrates many hypotheses of obesity. This includes the energy balance theory, which proposes that excessive food (and primarily fat) causes obesity, and the carbohydrate-insulin model, which considers carbohydrates at the centre of weight gain, the university’s press statement reveals. The study was published in the journal, Obesity.
“Essentially, these theories, which put a litany of metabolic and dietary drivers at the centre of the obesity epidemic, are all pieces of a puzzle unified by one last piece: fructose,” says Johnson in the statement. “Fructose is what triggers our metabolism to go into low power mode and lose our control of appetite, but fatty foods become the major source of calories that drive weight gain.”
For instance, when we are hungry and low on active energy, we activate the survival mode. Similarly, animals forage for food when energy levels are low, which is why hibernating animals such as bears eat fruit, which are high-fructose foods, to prepare for winter, Johnson explains. However, fructose significantly stifles active energy. While fat acts as stored energy, eating high-fructose foods block the replacement of active energy from fat storage, keeping it low like a bear preparing for hibernation during winter.
This theory views obesity as a low-energy state, says Johnson in the statement. “Identifying fructose as the conduit that redirects active energy replacement to fat storage shows that fructose is what drives energy imbalance, which unites theories,” he adds.
In July, another study, published in Philosophical Transactions of the Royal Society B, suggested that fructose may drive obesity because of the survival instinct that triggers the body to store energy from fructose instead of using it. Medical News Today reports.