Can you lose weight through exercise alone?

You want to lose weight. Knowing how to start a weight loss program can be a challenge and can be confusing. Should you do more exercise? Eat the same? Or just diet and do no exercise? The media often has conflicting views and makes it all look too simple. To cut through this, I’ve looked at the evidence from current research (this is research carried out on humans – not animals, that is peer reviewed and published in reputable journals and publications i.e. evidence based!)

1. Is just exercise enough?

In most individuals (although not all) exercise tends to increase appetite. This can result in eating more calories than you expended through the additional exercise.

In a recent study, a group of lean, overweight and obese women followed an 8-week exercise only program. The results showed a zero-fat reduction and interestingly, a significant increase in the hormone that controls hunger sensation (ghrelin) in the overweight and obese individuals.

According to the researchers, these hormonal changes could explain the lack of fat loss in the results. From this angle, exercise on its own is not enough to lose weight.

Looking at exercise with a more holistic approach though the research conclusively illustrates that exercise has many benefits beyond just weight loss. These are:

  • Mental health – hormones released through exercise are on par with taking antidepressants
  • Osteoporosis – weight bearing exercise prevents bone mineral loss and keeps bones stronger and healthier.
  • Muscle mass maintenance – As we age there is a natural decline in muscle mass (from the age of 35, 3%-5% per year).  But with muscle stimulation (weight training) and high levels of protein in your diet, muscle mass can be maintained and developed further.
  • Increased Insulin sensitivity – muscle metabolises carbohydrates far more efficiently than fat tissue mass. Having more muscle is a significant advantage in weight loss.

2. The calories paradox​

You can exercise everyday for the rest of your life, but if you’re eating too many calories you’ll never lose fat. Stop exercising to lose fat and commit to a structured exercise plan, as this is proven to:

  1. Get you fitter, stronger and healthier
  2. Improve your mental health
  3. Make you amazed at what your body is really capable of (which is a lot)

Apart from structured exercise there is Non Exercise Active Thermogenesis (shortened to ‘NEAT’, this includes things like fidgeting, walking, general moving etc., i.e. anything that isn’t actual exercise) research shows that NEAT is responsible for an average of 15% of our total daily energy expenditure, that’s a lot. So aim to walk more, move more in general throughout the day. This is low hanging fruit.

Throw NEAT into the mix with a structured exercise plan. Especially if your planned exercise is resistance training (with resistance training your body will continue to burn calories long after your training session is finished  for around 24-78 hours more!) You have significantly raised the bodies calorie consumption.

Exercise is starting to look very important in your weight loss goal.

3. What can we take from this?

It’s much more important to lose FAT than overall WEIGHT, because we want to keep muscle mass as high as possible. The literature shows converting fat to lean body mass (muscle) does not always show up as a lower weight on the scales. This is because muscle mass is denser than fat tissue mass (it takes up less space effectively). But we know it is much healthier and beneficial for optimum health.

Muscle tissue also burns more calories, so even if the scales haven’t shifted you will look and feel leaner and more toned.

This can only be achieved through exercise and a good high protein diet. If you lose weight through diet alone, it includes lean tissue loss and not just fat tissue.

​In a published study, overweight and obese post-menopausal women who followed a combined diet and aerobic exercise program lost more weight over the course of one year than women who followed a diet- or exercise-only program. Still the women who followed the diet-only program lost significantly more weight than the exercise-only group (8.5% vs. 2.4%), and only slightly less than the women who followed the combined program (8.5% vs. 10.8% for the combined approach).

​It’s not impossible to lose fat through exercise alone, but success will be far higher combining exercise with a healthy diet that hits a daily calorie target.

​From an evidence-based approach, diet and exercise not surprisingly is the best route to weight loss success.

An exercise program that is consistently followed, combined with a healthy calorie controlled diet that is adhered to, will produce results.