One of the most common errors in the press is the confusion between correlation and causation in scientific and health-related studies.

In theory, these are easy to distinguish … an action or occurrence can CAUSE another (such as smoking causes lung cancer), or it can CORRELATE with another (such as smoking is correlated with alcoholism). If one action causes another, then they are most certainly correlated.

But just because two things occur together does not mean that one caused the other, even if it seems to make sense.

In general, we should all be wary of our own bias. We like explanations. The media often concludes a causal relationship among correlated observances when causality was not even considered by a research study itself. Without clear and definite reasons to accept that one thing CAUSES another, the fact that a correlation exists is all we should accept. Again, two events occurring in close proximity does not imply that one caused the other, even if it seems to makes perfect sense.

Once upon a time, this type of error wasn’t too bad.
If one ate a berry and got sick, it was wise to see meaning in that data. (Better safe than sorry). The same goes for a red-hot coal. Only one touch will give all the correlations needed. Being bullied by a primitive world of nature, it's far worse to miss a link than it is to make one up. A false negative yields the greatest risk.

Now conditions are reversed.
People in modern civilization are bullies over nature. New claims about causation are often made so we can make large interventions in nature. A false positive today often means approving drugs that have no effect, or imposing regulations that make no difference, or wasting money in schemes to limit unemployment. Now, as science grows more powerful and government more technocratic, the stakes of correlation…. of making counterfeit relationships and bogus findings,… grow larger and larger. A false positive is now more burdensome than it's ever been. The only thing we have to fight this attitude is the catchphrase. “correlation is not causation”.

I suggest that we be very cautious in the way we allow media claims to influence us into making personal changes in our own behaviors, ... especially in relation to the way they tend to limit our personal choices of the foods we eat, and the way they tend to add to our personal expense and health risks through recommendions of unnecessary drugs. 

Mistaking correlation for causation finds a cause that simply isn't there.

                              
Which is better or most effective, cutting Carbs, or cutting Calories?

Everything I’ve seen and experienced personally, leads me to believe that calories matter even when one chooses to eat low-carb. There’s a possibility that one can eat a few more calories by reducing carbs, but … for most people … the amount of extra calories doesn't appear to be a very large number.

 It seems like there are an endless number of specific diets and rules for weight loss. One of the most popular of these rules is that cutting carbohydrates (carbs) is the best way to lose weight.

The Atkins diet, first popular in the 1970s.is the most famous low-carb diet. This diet recommends limiting foods high in carbs, such as bread, pasta, rice, and starchy vegetables such as corn and potatoes. Carbs are replaced with foods containing a higher percentage of proteins and fats (meat, poultry, fish, eggs and cheese) and other low-carb foods (mostly vegetables).

What does the evidence show us about whether low-carb diets really are better for weight loss and weight-maintenance than other diets?

Conventional wisdom says that a “calorie is a calorie” and it doesn't matter what types of food the calories come from, and therefore, all reduced-energy (calorie) diets should lead to equivalent weight loss.

However, some studies have reported that low-carb diets, in the short-term, lead to greater weight loss than other types of diets. What are some possible explanations for these results?

1. Changes in body composition

Energy is stored in the body as protein, fat, and glycogen, which is a form of carbohydrate. If there is an imbalance between how many of these nutrients are ingested (through the food that is eaten) and how many are used by the body for every day functions, body composition will change.

In turn, this will affect body weight because of the different impact that the relative amounts of stored protein, fat and carbohydrates have on body weight.

However, the vast majority of studies in which they’ve measured calorie intake very accurately (that is, they’ve locked people in a room and measured exactly what they’ve eaten for several days), show absolutely no difference in weight loss based on the composition of the diet. High-protein diets and high-carb diets resulted in the same weight loss.

2.  Changes in metabolic rate

The body’s metabolic rate (the amount of energy expended by the body in a given time) is dependent on the composition of the diet. Consumption of protein, for example, is known to result in a larger increase in energy expenditure for several hours after a meal compared with the consumption of fat or carbs.

But the overall effect of diet composition on total energy expenditure is relatively small. As a result, the assumption that a “calorie is a calorie” is probably a reasonable estimation as far as energy expenditure is concerned.

3.  Changes in hunger levels and satiety

Some diets can lead to reduced hunger, improved satiety (feeling full), and can be easier to stick to than others. There is an enormous amount of research on this.

The problem is that it’s extremely difficult to accurately measure what people are eating over extended time periods. In general, people rarely stick to their diets for more than just a few weeks, making it almost impossible to adequately compare the effects of different diets.

And so, is cutting carbs the best way to lose weight?  Maybe.

However, all diets with similar calorie content appear to have a similar effect on weight loss in the long-term. This is probably because the body adapts rapidly to changes in relative protein, fat and carbohydrate intake levels.

The truth is that losing weight and keeping it off in the long-term is difficult. It requires permanent changes to the number of calories you eat each day. My own maintenance struggle has involved experimenting with many different diets, or ways of eating.

  I believe the best diet for a person, is whatever diet that person is able to live with comfortably long-term. My own maintenance involves a continual process of looking for a way of eating that satisfies that criteria for me, personally.  As a part of that process, I’ve made Dieting into a rather enjoyable Hobby for myself, which is why this website is named DietHobby.

                             

Although almost every weight-loss expert seems to have something to sell,
...... despite the marketing hype ,...... there are kernals of truth in many of the basic things they say.
 

"Science has failed us in the weight loss department.
It literally gets an “F.”

The culture has failed us as well. Far too many people have intense moral judgments towards anyone with excess pounds, which contributes to the hidden epidemic of social disconnection, apathy, and plain old sadness.

Let’s face it: when it comes to the subject of weight gain and weight loss, we’re clueless.  And from that place of cluelessness we tend to flail around, we try our hand at the most inane weight loss strategies, we diet for decades, we consume diet foods ...that are, if you care to closely study the scientific literature ... toxic."

                    Marc David - Psychology of Eating

                             
It's hard not to binge on delicious food. For more about that experience, go to the bottom of the page, and Watch an entertaining video at the end of this article.

However, that is NOT the ONLY reason why weight-loss is hard.  I've been reading about "Adaptive Thermogenesis" .  Physical systems (like machines) stay the same.  Biological systems (like humans) adapt.

Weight-loss and maintenance have less to do with motivation and will-power than most people think. In fact it has far more to do with how your body adjusts to, and is capable of, resisting a calorie deficit. Putting less fuel in the tank of one's car will always cause the car to drive a shorter distance.  However, the human body adapts to less fuel ....meaning eating fewer calories.... by becoming more ‘efficient’ and running the same distance on less fuel than before. That is the big difference between simple physics and biology

For a better understanding of the issue of energy-in/energy-out, read my Summaries of what Gary Taubes has to say about it. 
WWGF - Chapter 6 Thermodynamics for Dummies, Part 1
and Chapter 7 Thermodynamics for Dummies, Part 2.

Here is a great article by Dr. Arya Sharma M.D. on this issue:

The Role of Adaptive Thermogenesis in Resistance to Weight Loss

No intentional weight loser continues to lose weight till she disappears.

Sooner or later every diet, every medication, or every type of bariatric surgery will result in a weight loss ‘plateau’ (better referred to as a ‘floor’) - a weight, beyond which losing even more weight (and keeping it off) becomes an almost ’super-human’ feat.

However, there is considerable variation in how much weight people can lose and keep off. Although the average sustainable weight loss with ‘eat-less-move-more’ (ELMM) approaches is about 3-5% of initial weight, some folks manage to lose considerably more, while others struggle to even simply stop gaining weight.

This has less to do with motivation or will-power than most people think.
In fact, it has far more to do with how your body adjusts to and is capable of resisting a calorie deficit.

While putting less fuel in the tank of your car will consistently decrease the distance that you can drive, our bodies adapt to less fuel (i.e. eating fewer calories) by becoming more ‘efficient’ and running the same distance on less fuel than before. That is the big difference between simple physics and biology.

Biological systems adapt - physical systems (like your car) stay the same.

In the case of humans (and animals) we call the adaptation of energy needs and expenditure ‘adaptive thermogenesis’. Exactly how adaptive thermogenesis is regulated and how differences therein can largely determine both weight loss and weight regain, is the topic of a paper by Angelo Tremblay and colleagues from the Universities of Laval and Ottawa, published in the International Journal of Obesity.

As the authors point out,

“The decrease in energy expenditure that occurs during weight loss is a process that attenuates over time the impact of a restrictive diet on energy balance up to a point beyond which no further weight loss seems to be possible. For some health professionals, such a diminished energy expenditure is the normal consequence of a progressive decrease in the motivation to exercise over the course of a weight-reducing program.”

Many studies have now documented the process of ‘adaptive thermogenesis’, whereby weight loss is associated with a ‘greater-than-predicted’ decrease in energy expenditure. This occurs both through a reduction in metabolic rate as well as through an often remarkable increase in ‘fuel efficiency’ related to physical activity, whereby individuals, who have lost weight burn far fewer calories for the same amount of physical activity than before losing their weight (far more than can be explained simply by considering that they are also moving less weight around).

As the authors discuss, not only do people, who demonstrate the greatest decrease in adaptive thermogenesis in response to weight loss tend to lose less weight (for the same level of caloric restriction) but they also tend to have a greater increase in hunger and appetite.

Also, it does not appear that these ‘adaptive’ responses to weight loss diminish over time, which means that the resistance to further weight loss and the propensity to weight regain persist till the weight is eventually regained (i.e. they once again ‘fail’).

Together, these factors can easily explain why losing weight and keeping it off is far more difficult for some folks than for others - irrespective of motivation or will power.This basic biological fact is not only important to ‘dieters’ (even if it seems demotivating) - but perhaps even more important for all health professionals to be aware of.

Simply ‘blaming’ people who find it harder to lose weight or keep it off for their lack of will power or motivation, is neither fair nor helpful. You can only fight your biology so far before life is no longer fun - this is when you need to realize that you are now living below your ‘Best Weight’.

AMS
Edmonton, Alberta

Tremblay A, Royer MM, Chaput JP, & Doucet E (2012). Adaptive thermogenesis can make a difference in the ability of obese individuals to lose body weight. International journal of obesity (2005) PMID: 22846776

Dr Arya Sharma, M.D. 
Dr. Sharma’s Obesity Notes   www.drsharma.ca

 

                           
I've been feeling frustrated by my current maintenance results, a web search about that issue turned up an article about a study of literature on the subject, which I found interesting, even though it wasn't particularly helpful to me.

Below is part of that article, originally published in Medscape on 1/6/2012

Psychological Factors Influencing Weight Loss Maintenance

Background.
It is well recognized that most individuals who lose weight are unable to maintain that weight loss. However, the lack of evidence about the factors that cause this regain is surprising. The purpose of this study was to review the available literature to try and identify the factors that are most consistently linked with weight regain and propose strategies to assist patients to maintain their success.

Methodology.
An electronic search identified studies of patients whose weight loss had been achieved through behavior modification and who were then followed for the subsequent 12-18 months. Included studies were determined to have good methodological rigor and relevant data.

Results.
The literature on factors potentially contributing to weight regain were examined and clustered into 8 categories:

1. Unrealistic weight loss expectations -- studies were mixed and it cannot be concluded that this issue is a consistent predictor of weight regain.

2. Failure to achieve weight loss goals -- satisfaction with one's initial weight loss was identified to be an important factor. Those able to reach their goal weight or, alternatively, those who were satisfied with their weight loss even if it was less than their original goal were more likely to maintain this loss.

3. Dichotomous thinking -- this is defined as a "black or white" thinking pattern that leads to difficulty in accepting anything less than the original goal. This type of thinking pattern was strongly predictive of unsuccessful weight maintenance.

4. Eating to regulate mood -- another strongly predictive factor identified in this review was use of food to relieve emotional distress.

5. Disinhibition vs dietary restraint -- higher levels of disinhibition, which led to more uncontrolled eating, were associated with weight regain. In contrast, those able to maintain weight loss were better able to exercise restraint in their eating.

6. Perceived cost vs benefit -- individuals able to successfully maintain weight loss continue to find that the benefits of weight loss, whether defined as improved appearance, better health, or some unique combination of benefits, outweighed the perceived costs of weight maintenance strategies such as regulation of diet or exercise.

7. Depression -- although depression has clearly been linked to obesity, its relationship to successful weight loss maintenance is less clear. Baseline depression was not necessarily a factor, but increasing levels of depression over the time of weight maintenance did predict regain.

8. Body image -- no surprise, individuals who were more satisfied with their appearance, with steady improvement in body image throughout the time period studied, were more likely to maintain their weight loss.

None of this is really news, but it's worth thinking about again. I found their Viewpoint summary to be rather standard and uninteresting. I found the following statement particularly uninspiring….

"A number of factors associated with unsuccessful weight maintenance
are the same as those seen in patients with binge eating disorder."

 Like DUHHHH!! Don't even get me started on what I think about the way every single "non-healthy" eating behavior is now being labeled an "eating disorder".

Uh Oh, 
I think my frustration is clearly showing here again, and so now I'm going to spend some time working on my Positive Thinking.