Weight loss is often described as journey, with the attainment of the goal weight seen as the end of this journey. Unfortunately this way of looking at things fails to take into account the struggle of maintaining weight loss, with some studies estimating that up to 90% of people who successfully lose significant amounts of weight will slowly see that weight creep back on over the next few years. A weight loss journey is ongoing, but in the absence of a regimented diet and exercise plan, a lot of people can't resist the tendency to return to old habits
One of the major contributors to rebound weight gain is the fact that people have a lower calorie requirement (REE or Resting Energy Expenditure) after weight loss. This makes sense, because more energy is going to be required to maintain a larger body. What is puzzling is the fact that after weight loss, people tend to become more sedentary. Studies have shown that people who have lost weight, on average, expend less non-exercise energy, or have a lower Non Exercise Activity Thermogenesis (NEAT). NEAT includes energy used on incidental activities, like walking, standing and fidgeting, and for some reason it drops after weight loss, meaning the body is burning less energy overall.
Exercise is a wild card in all this. Exercise increases the amount of calories burned, but bizarrely, in many people, it does not actually have a significant bearing on weight loss, compensatory eating thought to be the main culprit for this lack of efficacy. On the other hand, studies have shown that exercise can prevent people from regaining weight. A group of American scientists recently decided to look at this tricky relationship between weight loss, exercise, activity and metabolism.
The team recruited 140 overweight women, who were divided into three exercise groups – no exercise, cardio three times a week, and weight training three times a week. Each woman was placed on a low calorie diet, which she followed until she had lost 25 pounds, at which point, she was placed on a diet designed to keep her weight stable. Each woman was then monitored for a month while continuing her prescribed exercise regime. Different types of energy expenditure were measured in the weight loss maintenance period.
As expected, all three groups of women had a reduced resting energy expenditure (REE) after weight loss. Big differences, however, were observed between the women in the exercise groups, and the sedentary group. When researchers looked at total energy expenditure between groups, they realised that the groups who were exercising were burning energy at only a slightly lower rate overall than they were before the weight loss, while the non-exercisers saw a big drop in their total energy expenditure. When this was examined further, major differences were seen in the levels of non-exercise energy (NEAT) burnt by respective groups - the women who were performing regular exercise were moving round a lot more during their day to day activities and keeping a lot more active than their sedentary counterparts. The NEAT energy expenditure was only slightly below pre-weight loss levels in both exercise groups, but the effect was most pronounced in the weight training group, many of whom actually increased their NEAT energy expenditure post-weight loss. One of the reasons put forth for this was the increase in movement economy seen in the exercisers – these groups reported that movement felt a lot easier, and as a result they moved more. The opposite was seen in the non-exercising group who surprisingly found movement more difficult, even after losing a significant amount of weight. Weight loss is hard and keeping it off is even harder. One thing that's for sure is that it's not as straightforward as we first thought.
It seems that every time you read the news, another benefit has been discovered for resistance training, and more men and women are turning to the weights as a challenging, enjoyable, and seemingly more beneficial alternative to the monotony of slogging it out on the treadmill, and it could be the key to breaking out of your weight loss/weight gain cycle. Why not give it a go!
Hunter GR, Fisher G, Neumeier WH, Carter SJ, Plaisance EP. Exercise Training and Energy Expenditure following Weight Loss. Med Sci Sports Exerc. 2015 Jan 20.