An unexpected discovery has shown that certain widespread beliefs about healthy eating habits may be false, and actually causing people to put on weight.

The finding came from a researcher at the University of British Columbia and was published in Cell Metabolism.

The study set out to observe the role of insulin, which is hormone that permits the body to store blood sugar so that it can be used as energy later on. A lack of insulin causes diabetes, and, according to a different study in the same journal, impaired brain insulin action may be the cause of the unrestrained lipolysis which results in, and worsens, type 2 diabetes.

After analyzing the role of insulin in animals, James Johnson, an associate professor or cellular and physiological sciences, discovered that too much insulin may be detrimental.

Johnson split mice into two groups and provided both with a high-fat diet. One group, the control group, consisted of normal mice and the other consisted of mice which were bred to have only half the regular amount of insulin.

Results showed that the normal mice became overweight, just as the scientist anticipated. However, the mice that had low levels of insulin did not gain weight due to the fact that their fat cells burned more energy while storing less. The mice that remained skinny had less swelling and had livers that were in better health.

This meant, according to Johnson, that obesity resulted from the additional insulin that was made in the normal mice by the high-fat diet. In other words, mice, as well as humans, may produce more insulin than necessary.

The research indicates that people can maintain a healthy weight by constantly bringing the levels of insulin back to a healthy minimum. This can be done by increasing the time between meals and eliminating snacks, without making amends at mealtime.

The general belief that people should eat small amounts of food throughout the day in order to stay slim was shown to be ineffective in this study.

Johnson concluded:

“As crucial as insulin is for storing blood sugar, it can also be too much of a good thing. If we can maintain insulin levels at a happy medium, we could reverse the epidemic of obesity that is a risk factor for so many ailments – diabetes, heart disease, and cancer.”

Considering that Johnson, a member of UBC’s Life Sciences Institute, did not conduct research to examine obesity, he was quite surprised with what he found. He originally set out to determine whether beta cells in the pancreas, which are insulin-producing, were encouraged to increase by their own insulin secretion.

Both of Johnson’s discoveries were unanticipated:

  • mice with low-insulin were not able to gain weight
  • the majority of those mice, even with significantly reduced insulin levels, still did not develop diabetes

According to measured height and weight data from 2007-2009, an estimated 1 in 4 adults in Canada struggles with obesity. Obesity rates increased two times among males and females in several age groups between 1981 and 2007-9.

Although there are drugs that block insulin and prevent people from putting on weight, they have adverse effects that cancel out the medications’ advantages. More studies need to be conducted in order to develop drugs that can block people from producing extra insulin or alter its impact on specific targeted tissues.

Written by Sarah Glynn