Have you ever wondered why it is so hard to lose weight and so easy to gain it back?

If you have been on a diet before, you may have noticed that it is much easier to lose weight in the first few months.  In the first three months or so, the number on the scale seems to consistently go down from week to week. You are filled with joy and euphoria of success.  Just when you are beginning to feel confident, something discouraging begins to happen.  The scale is no longer moving as fast.  Worse still you start to regain weight.  Before long you are frustrated and give up.  After some time you work up enough determination to try again.  To your disappointment the things you did in the past do not seem to work as well. 

This is the experience of millions of dieters.  The reason for this is metabolic adaptation.  This is the brain’s response to weight loss.  The human brain is programmed to defend against when loss.  The brain can tell that you are losing weight by monitoring the level of a hormone called leptin.  Leptin is made in the fat cell.  Leptin is the satiety hormone that tells your brain that you are satiated after a meal.  It also relays to the brain the amount of fat reserve you have.  When you lose weight, the level of leptin drops.  The brain’s response to this causes the release of about eight different hormones that result in the following:

  • Decrease in metabolic rate.  Your tissues burn less calories for any given activity than they did prior to weight loss.  This is also known as adaptive thermogenesis.
  • Increase in hunger due to increase in the level of hunger hormone call ghrelin.
  • Decrease satiation due to decrease in the level of leptin
  • Release of dopamine as a reward for eating food high in sugar, fat and salt. 

The net effect of these changes is to regain the weight you have lost. 

The system was put in place because for most of human existence, body fat was a survival advantage.  Humans needed body fat to survive famine and winter.  However, civilization has given up access to good food and homes with insulation.  We are no longer in danger of dying from famine or hypothermia. It is the mismatch between civilization and evolution that is at the heart of the epic struggle to lose weight and keep it off.  This is why long-term weight loss has eluded many dieters.

  As a dieter, do a few things to control metabolic adaption such as,

  • Exercise.  Regular exercise cand decrease the wave of hormonal response to weight loss.  Exercising an hour or more a day for at least five days a week could help to attenuate the hormonal response to weight loss.
  • Medications.  There are several weight loss drugs that can help with this problem.  The exciting news is that the newer drugs are proving to be very effective.
  • Bariatric surgery is also effective.

If you are doing all you can to lose weight and still struggling, it is most likely due to metabolic adaptation.  Ask a healthcare provider for treatment options because willpower is not enough.

Ife Ojugbeli, MD, MBA.