LOSING, GAINING AND SET POINT THEORY
Seems there's an awful lot going around these days about how tough it is to lose weight and, most importantly, how impossible it is to keep it off. That alone may not be news to you, but what's being put forward more and more frequently as the explanation for this is known as the Set Point Theory. I wrote about one aspect of this in my January newsletter earlier this year, and have since discovered that this theory is considerably more widespread than I had at first realised.
For example, a number of UK newspapers recently reported on the idea that metabolic rate slows whenever weight has been lost. In other words, as we lose fat from our bodies, we need even fewer calories in order to maintain that lower weight. Which means we'll regain the weight if we then don't eat even less. Sounds like a nightmare! (1)
The Set Point Theory states that your body somehow prefers a certain weight, and will automatically set biological reactions in motion in order to stay at that weight. Slowing down the metabolic rate is said to be one of those reactions. Changing the release of appetite hormones (in charge of our experience of hunger and fullness) is said to be another. There may well be other mechanisms that may or may not have been identified.
If, for example, my Set Point is 160lbs and I go on a diet and lose, say, 40 of those lbs, my body will make me regain those 40lbs, overriding my best efforts to stay slimmer. The phrase that's often used to describe Set Point Theory is that "the body biologically defends the elevated level of body fat mass."
The most significant point about this Theory is that the Set Point can become elevated. No explanation has been given as to why a body would defend an elevated level of body fat, and not an optimal, healthy level. Nobody knows how we end up with a Set Point that's too high, and nobody has found a way to adjust it back down.
Follow me here, because I want to explain a real problem with this Theory.
Let's say I'm beginning yet another diet, starting at that 160lbs, and I lose steadily for 6 months until I'm 120lbs. I realize that you may not have done this, but this is not uncommon. There are people in this overweight world who embark on such a strategy and achieve weight loss of, say, 40lbs. It happens.
What we also know is that this weight loss is highly unlikely to be maintained over time, and, according to Set Point Theory, it's my body that's going to drive me back to my starting weight - or maybe even more. If we plotted this loss and gain, over time, on a graph, it would form some kind of a "U" shape. The flaw in logic is this. If my body makes it impossible for me maintain weight loss after 6 months, why doesn't it do this after 6 weeks? Or 3? Or 2? If my body resists being, for example, 140lbs on the right side of that U-curve while I'm gaining, why does it not do that when I'm 140lbs on the left side while I'm losing?
One could argue that the body does resist the loss, which is why losing weight is such a struggle. But why it is a struggle I win at first and fail at later? If this were due to biological systems, no matter what they are, it wouldn't make any difference.
Set Point Theory says that if my Set Point is 160lbs and I'm currently 140, my body will...
1. make me feel more hungry and/or less satisfied so that I eat more
2. raise the caloric significance of what I eat
...and it will do that at least until that last 20lbs is regained.
But in my example above, this didn't kick in when I was 140 on the left, weight-loss side of that U-curve.
The only biological difference between me at 140lbs on the losing side and me at 140lbs on the gaining side is that I'm eating more on the latter, which is why I'm gaining weight instead of losing. But Set Point Theory is said to explain why I'm eating more food (appetite hormones). Otherwise, we've just got a theory that says, eat less and you lose weight; eat more and you gain. And that's not Set Point Theory.
By the way, eating less in general is the way to lose weight, but eating fewer calories from carbohydrates will do the job faster and better, especially if you are eating a good amount of protein. Calories from proteins turn into healthy lean mass, rather than calories from carbohydrates, which turn into unhealthy storage fat. The benefit is a raised metabolic rate because the body can maintain - and even develop - lean mass, and lean mass burns seven times as many calories as fat. (2-5)
In addition, it's by no means certain that the slowed metabolic rate after weight loss is either large enough or lasts long enough to make any difference. One study concludes:
"Our findings do not provide evidence in support of adaptive metabolic changes as an explanation for the tendency of weight-reduced persons to regain weight." (6)
I don't like to question one theory without making a case for an alternative. Returning to that U-shaped graph, the difference between me at 140lbs while losing and me at 140lbs while gaining is psychological and it's this - potentially huge - psychological difference that my work targets.
Lost weight is frequently regained because:
- Most people set out to eat less in order to lose weight, and this is their primary or even exclusive motivation. This is problematic for a number of reasons, the most common being that once the weight has been lost, the motivation to eat less is lost as well - or at least substantially weakened.
- Most people try to lose weight by complying with prohibitions, either their own rules or those taken on from others. This sets up a state of deprivation: feeling restricted, craving and missing out. At some point - either when the weight is lost or when enough rules have been broken - rebellious overeating kicks in, along with the inevitable weight regain.
- We are surrounded by highly attractive, tempting stuff to eat. Once you let go of any judgment you may have about it, naming overeating as an addiction is actually helpful. If the addictive relationship with food is not addressed - and it is almost universally avoided - relapse follows.
Most smokers have stopped smoking at some point, but they didn't stay stopped, and addiction is the reason. Some smokers, however, do stay stopped, and some of those who overeat lose their excess fat and maintain that weight loss. In both cases, the process is one of changing the addictive mind set.
Real change of any kind is only possible through changes in brain function: change the way you think and you change your behaviour in ways that last.
- "Why shedding the pounds is twice as hard as you think." Daily Mail, February 21, 2012 (story also appeared in The Guardian and The Independent)
- "Effect of dietary protein content on weight gain, energy expenditure, and body composition during overeating." Bray GA, Smith SR (2012) Journal of the American Medical Association 307(1): 47-55
- "Greater fructose consumption is associated with cardiometabolic risk markers and visceral adiposity in adolescents." Pollock NK, Bundy V (2012) Journal of Nutrition 142(2): 251-7.
- "Increased ratio of dietary carbohydrate to protein shifts the focus of metabolic signaling from skeletal muscle to adipose." (2011) Devkota S, Layman DK Nutrition and Metabolism (London) 8(1):13
- "Dietary protein, weight loss, and weight maintenance." Westerterp-Plantenga MS, Nieuwenhuizen A. (2009) Annual Reviews of Nutrition 29:21-41.
- "Do adaptive changes in metabolic rate favor weight regain in weight-reduced individuals?" Weinsier RL, Nagy TR (2000) American Journal of Clinical Nutrition 72(5): 1088-94.