Dr. Sharma's Obesity Notes

I am currently in New Delhi enjoying daytime temperatures of 45 degrees Celsius – I’d forgotten how hot this can be.

A good opportunity to take a look at recent literature on obesity in India, where this is clearly becoming an increasing problem – India now has the largest number of people with obesity (using the South Asian definition of BMI 25)  and perhaps the most people living with diabetes anywhere in the world.

An article that caught my eye is the recent analysis of the relationship between the consumption of milk and milk products and obesity by Satija and colleagues from the Public Health Foundation of India, New Delhi, published in PLoS One.

As anyone familiar with Indian cuisine is well aware, milk in its various forms including plain milk, in tea (where tea leaves are traditionally boiled at length in watered down milk), curd, and buttermilk (often consumed as lassi) is considered a staple of the Indian diet and apart from lentils (another staple), often the only significant source of protein for the vegetarian masses.

Information on dairy consumption assessed using a Food Frequency Questionnaire was obtained from the cross-sectional sib-pair designed Indian Migration Study (3698 men and 2659 women), conducted at four factory locations across north, central and south India.

After controlling for potential confounders, the risk of being obese (BMI≥25) was almost 50% lower among women among those who consume one or more portions of plain milk daily than those who did not consume any milk.

On the other hand, daily tea consumption of more than one portion was associated with a 50% increased risk of obesity and increased waist circumference in men but not among women.

There was no association between curd and buttermilk/lassi consumption with obesity and high waist circumference among either men or women.

Thus, there appears to be an inverse association between the daily consumption of plain milk with the risk of being obese, but the authors hasten to add that this is merely an association and does not imply causality. In plain english, this means that we should not rush to conclusion that decreased milk consumption should be added to the list of possible causes of obesity in South Asia or that drinking more milk will help my Indian brethren lose weight.

On the other hand, given that there are several reasonable hypotheses linking adequate dairy intake to energy homeostasis, this is certainly an issue that may require further study.

I do recall that my grandfather, who lived to be a 104 and was always thin as a rail, would never go without his daily glass of warm milk before bedtime (but he’d also go for long brisk walks at 5 am every morning – so no conclusions can be drawn from this n=1 case study).

AMS
New Delhi, Arya

Obesity fact #7 in the New England Journal of Medicine paper on obesity myths, presumptions and facts, states simply that,

“Provision of meals and use of meal-replacement products promote greater weight loss.”

This “fact” is not surprising, as obviously if all you eat are the meals that are provided as part of a hypocaloric meal plan, then this is going to result in more weight loss than trying to compile those plans on your own.

Thus, as the authors rightly note,

“More structure regarding meals is associated with greater weight loss, as compared with seemingly holistic programs that are based on concepts of balance, variety, and moderation.”

While this may well be the case, the question ultimately is not just one of efficacy but also of effectiveness.

In other words, how likely, in the real world, is someone going to stick with a highly structured diet that essentially consists of meals delivered to your doorstep or even to meal replacements (rather than “real” food)?

While there are no doubt people who would fare well with such a regimen and would be willing to sacrifice variety for a plan that requires no effort in preparation and little effort in terms of decision-making, this may well be a minority of individuals.

While such strategies may well work to lose weight – the question really is whether such strategies results in long-term behaviour change that continues once you go back to eating “normal” foods in “normal” settings. Both cost and monotony could well be limitations of such approaches in the long term.

Nevertheless, I am certain that some of my readers will have their own experience with weight loss plans that either provide meals (e.g. Jenny Craig, Nutrisystem, etc.) or plans that involve replacing meals with bars or shakes (e.g. Slim-Fast).

That both strategies can be highly effective and promote weight loss is without question – they definitely work – whether such strategies are effective in the long-term (beyond the confines of a clinical trial) is perhaps less certain.

Obviously, any diet plan only works as long as you stick with it and there is probably nothing simpler or more convenient than having someone else prepare your meals for you.

AMS
Chicago, IL

Fact #2 about obesity from the New England Journal of Medicine paper states simply that,

“Diets (i.e., reduced energy intake) very effectively reduce weight, but trying to go on a diet or recommending that someone go on a diet generally does not work well in the long-term.”

This statement needs to be read very carefully as it actually comprises of two facts: the first alludes to the fact that reducing energy intake effectively reduces weight (which it no doubt does); the second to the fact that simply being asked to or wanting to go on a diet seldom results in long-term weight loss.

As the authors point out,

“This seemingly obvious distinction is often missed, leading to erroneous conceptions regarding possible treatments for obesity; recognizing this distinction helps our understanding that energy reduction is the ultimate dietary intervention required and approaches such as eating more vegetables or eating breakfast daily are likely to help only if they are accompanied by an overall reduction in energy intake.”

What the authors do not state, but is increasingly obvious (and would certainly count as a “fact” in my books), is that complex hormonal, metabolic and neurochemical changes associated with weight gain result in powerful biological adaptations that serve to defend against weight loss and to promote weight regain.

It are these counter-regulatory alterations, which include persistent changes in neurohormonal activation of appetite as well as marked reductions in resting and activity related thermogenesis, that together orchestrate the biological response to weight loss explaining why the vast majority of individuals, who lose weight with lifestyle interventions alone, fail to keep it off.

Simply stated, the failure of most diets has little to do with lack of motivation or will power – it has everything to do with the fact that the body very effectively “defends” its body weight and will ultimately wear down all but the most compulsively obsessed dieters.

This is not being “negative” about the success of dieting – this is simply acknowledging the reality of our biology.

It is also the rational explanation for the fact that most diets (irrespective of whatever happens to be the current fat: low-fat, low-carb, high-protein, or anything else) fail for most people and why true long-term “success stories” are indeed remarkably rare.

It would certainly help if fact #2 found its way not just into obesity policies but also into the realisation that obesity, once established, requires treatments that have to go well beyond meaningless and ineffective “eat-less-move-more” mantras.

AMS
Edmonton, AB

Obesity Presumption #5 in the myths, presumption and facts paper published in the New England Journal of Obesity, states that:

“Snacking contributes to weight gain and obesity.”

The underlying assumption is that snack foods are incompletely compensated for at subsequent meals, leading to weight gain.

However, as the authors note, neither randomised controlled trials nor observational data conclusively support this hypothesis.

This is not really a surprise, as snacking is not snacking is not snacking.

In other words, what really matters at the end of the day, is whether or not the calories consumed exceed the calories expended.

Indeed, some people may well find it easier to control their overall calorie consumption by snacking between meals, others may find that this simply leads to uncontrolled grazing.

The bottom line appears to be that this is not a question of whether snacking is good or bad – whether it is or not entirely depends on whether or not those snacks result in extra calories or are adjusted for in subsequent meals.

For some people, a healthy snack is probably the best way to ruin their appetite.

I wonder what my readers feel about this issue – does snacking help control overeating or simply make everything worse?

AMS
New York, NY

The 3rd Obesity Presumption in the New England Journal of Medicine on obesity myths, presumptions and facts paper states that,

“Eating more fruits and vegetables will result in weight loss or lessweight gain, regardless of whether one intentionally makes any other behavioral or environmental changes.”

The notion underlying this presumption is the common belief that,

“By eating more fruits and vegetables, a person presumably spontaneously eats less of other foods, and the resulting reduction in calories is greater than the increase in calories from the fruit and vegetables.”

While this may well be the case for some people, unless those fruits and vegetables are being eaten raw, chances are that they may well be contributing a significant amount of calories to your diet (think Indian vegetarian curry or a vegetable stir-fry).

It is therefore by no means surprising that simply going vegetarian (or even vegan) will do much for your weight even if it may take longer to eat the same amount of calories.

Thus, the studies quoted in this paper failed to find any impact on body weight by simply increasing fruit and vegetable intake without making any other adjustments to your diet – in the end what counts with regard to body weight are calories – irrespective of whether these are derived from vegetables, fruit, fats, oils, carbs, meats, dairy or alcohol.

If anything, this presumption should serve to remind us that eating healthier food is not the same as eating fewer calories.

AMS
Edmonton, AB