The mistake people make when they think about exercise and weight management is the perception that it's all about counting calories.
Exercise plays a significantly broader role in helping people maintain both a healthy body weight and lifestyle.
Forget, for a moment, the "ins and outs" of counting calories. Consider, instead, how regular exercise helps us in a much larger sense.
Let's start with the shot in the arm physical activity gives us in terms of mood, willpower and resilience.
For many people -- especially those who are overweight or obese -- their relationship with food is not straightforward. The connection between hunger and eating has been knocked off balance.
Stress eating and emotional eating are struggles for a great number of people. And obesity is frequently accompanied by depression, with the two often triggering and influencing each other, according to the American Psychological Association.
But even for people who don't grapple with depression or emotional eating, the fact remains that will power is not a bottomless pit; nor do resilience and the emotional energy needed to try again when you fall short of your dietary goals come easily.
Exercise helps people manage stress, sadness, anxiety and other emotions that can lead them to overeat. And according to the Mayo Clinic, regular exercise releases feel-good brain chemicals (neurotransmitters, endorphins and endocannabinoids), reduces immune system chemicals that can worsen depression, and increases body temperature, which may have calming effects.
Then there's the fact that exercise can help us sleep.
Research shows that there's a correlation between sleep and weight, with those who get too little sleep weighing more than those who get enough. Lack of sleep disrupts the balance of key hormones that control appetite (Harvard T.H. Chan School of Public Health). Exercise, however, can help improve sleep. There is even evidence that at the right times of day, exercise can have a positive effect on our circadian rhythms -- or inner clock -- which is important for quality of sleep and other health issues.
Consider, as well, the powerful and time-tested finding that exercise is the most commonly shared behavior among those who have lost weight and kept it off for the long term. The National Weight Control Registry shows plainly that 90 percent of those who have lost weight and kept it off exercise about an hour a day on average. The database shows that Registry members have lost an average of 66 pounds and kept it off for 5.5 years.
The most compelling reason to exercise, however, may be for the health benefits it brings. If for no other reason, we all should be physically active simply because it increases the odds that we will be able to maintain a healthy diet and lifestyle.
By helping to protect against heart disease, Type 2 diabetes, stroke, osteoporosis, Alzheimer's disease, depression, and even some cancers, regular exercise helps to protect us against physical and mental decline.
All told, it is far easier to fall prey to poor lifestyle habits and dietary choices when we're demoralized by poor health. Feeling good is motivational, and motivation helps people make smart decisions.
If only maintaining a healthy weight and lifestyle were as simple as calorie counting and educating people to eat less and better.
But it's not.
Exercise really is the steadfast cornerstone of a healthy weight and lifestyle. Indeed, it's the very foundation on which we all can build our wellbeing.
HuffPost Lifestyle is a daily newsletter that will make you happier and healthier — one email at a time. Learn more