Metformin Attenuates Long-Term Weight Gain in Insulin-Resistant Adolescents
The biguanide metformin is widely used for the treatment of type 2 diabetes. Metformin has also been shown to slow the progression from pre to full-blown type 2 diabetes. Moreover, metformin can reduce weight gain associated with psychotropic medications and polycystic ovary syndrome. Now, a randomised controlled trial by M P van der Aa and colleagues from the Netherlands, published in Nutrition & Diabetes suggests that long-term treatment with metformin may stabilize body weight and improve body composition in adolescents with obesity and insulin resistance. The randomised placebo-controlled double-blinded trial included 62 adolescents with obesity aged 10–16 years old with insulin resistance, who received 2000 mg of metformin or placebo daily and physical training twice weekly over 18 months. Of the 42 participants (mean age 13, mean BMI 30), BMI was stabilised in the metformin group (+0.2 BMI unit), whereas the control group continued to gain weight (+1.2 BMI units). While there was no significant difference in HOMA-IR, mean fat percentage reduced by 3% compared to no change in the control group. Thus, the researcher conclude that long-term treatment with metformin in adolescents with obesity and insulin resistance can result in stabilization of BMI and improved body composition compared with placebo. Given the rather limited effective options for addressing childhood obesity, this rather safe, simple, and inexpensive treatment may at least provide some relief for adolescents struggling with excess weight gain. @DrSharma Edmonton, AB
How Do People With Obesity Spend Their Time?
We live in a time where most of us complain about the lack of it. Thus, I often remind myself that our “fast-food culture” is more a time than a food problem. Now a study by Viral Patel and colleagues, published in OBESITY, takes a detailed look at how US Americans spend their time according to different BMI categories. The researchers analyse data from over 28,503 observations of individuals aged 22 to 70 from the American Time Use Survey, a continuous cross-sectional survey on time use in the USA. In a statistical model that adjusted for various sociodemographic, geographic, and temporal characteristics, younger age; female sex; Asian race; higher levels of education; family income >$75 k; self-employment; and residence in the West or Northeast census regions were all associated with a lower BMI relative to reference categories whereas age 50 to 59 years; Black, Hispanic, or “other” race; and not being in the labor force were associated with a higher BMI. That said, here are the differences in time use associated with higher BMI: Although there were no substantial differences among BMI categories in time spent sleeping, overweight individuals experienced almost 20 fewer minutes of sleeplessness on weekends/holidays than individuals with normal weight. Furthermore, there was a U-shaped relationship between BMI and sleep duration such that BMI was lowest when sleep duration was approximately 8 h per day and increased as sleep duration became both shorter and longer. Less sleep on weekends and holidays (5 to 7 h) was also associated with higher BMI than 8 to 9 h or sleep. There were also no major differences between BMI categories and the odds of participating in work or in the amount of time working. However, working 3-4 h on weekends/holidays was associated with the lowest BMI. Individuals with obesity were more likely to be working between 3:30 a.m. and 7:00 a.m. on weekdays than normal-BMI individuals, again perhaps cutting into restful sleep. Individuals with obesity were less likely to participate in food and drink preparation than individuals with normal weight on weekdays but spent about the same amount of time eating or drinking as the reference category. Interestingly, individuals with obesity were more likely than individuals with normal weight to participate in health-related self-care, and overweight individuals spent over 1 h more on weekdays than individuals with normal weight on health-related self-care and also spent an additional 15 min (almost double… Read More »
Effectiveness of Exercise Interventions After Bariatric Surgery
There is no doubt that exercise is good for you and that individuals with obesity, both before and after bariatric surgery (like everyone else), would stand to benefit from increasing their levels of physical activity. Following bariatric surgery, exercise may be particularly important not just to increase physical fitness, but also to limit the obligatory loss in muscle mass that generally accompanies weight loss. Now, a study by David Creel and colleagues, published in OBESITY, compares three levels of exercise intervention in patients following bariatric surgery in terms of effectiveness and adherence. A total of 150 patients undergoing bariatric surgery were randomised to either standard care (SC), pedometer use (P), or exercise counseling group (C). The standard care group (SC) received no exercise support by the bariatric center beyond a simple educational pamphlet. Participants in the pedometer group (P) were given a pedometer and a one-page information sheet on using the device to increase physical activity. This handout promoted the progressive attainment of 10,000 steps/day. Individuals were asked to wear their device daily and record date, steps achieved, and whether they wore the device the entire day, part of the day, or not at all. Journals were collected, but no feedback was provided. Participants in the exercise counselling group (C) were regularly seen at the bariatric centre and counselled by a certified exercise professional using motivational intervention techniques with individual goal setting. Based on physical activity measurements using an accelerometer over two weeks before and 2, 4, and 6 months postoperatively, there was no difference between the SC and P groups, with a statistically significant but modest increase in daily steps in the C group that emerged at 4 months and was maintained at 6 months (about 1,000 extra steps per day compared to SC). There was no notable difference in exercise tolerance, which increased in all three groups post surgery. No group reached the 10,000 steps/day or 150 bout-minutes/week recommended for general health As may be expected from these rather modest results, no significant differences in weight or weight change were found between groups at any time point. Thus, these findings suggest that handing out a pedometer and asking patients to journal their activity is no more effective in promoting physical activity, than simply handing out a pamphlet; moreover, even adding in counselling by an exercise professional adds little (if anything) to the outcome. Although the researchers discuss the possibility that an even more intense intervention may provide… Read More »
Bariatric Surgery Improves Mitochondrial Efficiency
One of the more frustrating aspects of weight loss, is that it is often associated with decreased metabolic rate and increased ‘fuel efficiency’. Thus, following weight loss, not only does the body need fewer calories, doing the same amount of physical work uses fewer calories than before (the joke is that, if you ran 5K a day to lose weight, you have to run 10K a day to keep it off). Now, a study by Maria Fernström and colleagues, published in Obesity Surgery, shows increased mitochondrial efficiency following bariatric surgery. The researchers performed skeletal muscle biopsies in 11 women before and at 6 months after gastric bypass surgery. Measurements in isolated mitochondria showed a marked increase in coupled respiration (state 3) and overall mitochondrial capacity (P/O ratio) with a non-significant increase in uncoupled (state 4) respiration. Thus, at 6 months following gastric bypass surgery, both the mitochondrial capacity for coupled, i.e., ATP-generating, respiration increased as well as the P/O ratio improved. As the authors note, not only would this increased “fuel efficiency” in part explain the decreased basal metabolism often associated with weight loss but also the propensity for weight regain that often follows weight-loss interventions. Obviously, due to lack of a control group, this study does not demonstrate that these changes are in any way specific to weight-loss following bariatric surgery. Also, given that the nadir of weight loss is generally not achieved until about 18 months following surgery, the changes observed in this study may not represent the maximum increase in mitochondrial efficiency to be achieved with further weight loss. @DrSharma Edmonton, AB
Arguments For Calling Obesity A Disease #8: Can Reduce Stigma
Next, in this miniseries on arguments for and against calling obesity a disease, I turn to the issue of stigma. One of the biggest arguments against calling obesity, is the fear that doing so can increase stigma against people living with obesity. This is nonsense, because I do not think it is at all possible for anything to make stigma and the discrimination of people living with obesity worse than it already is. If anything, calling obesity a disease (defined as excess or abnormal body fat that impairs your health), could well serve to reduce that stigma by changing the narrative around obesity. The current narrative sees obesity largely as a matter of personal choice involving poor will power to control your diet and unwillingness to engage in even a modest amount of regular physical activity. In contrast, the term ‘disease’ conjures up the notion of complex biology including genetics, epigenetics, neurohormonal dysregulation, environmental toxins, mental health issues and other factors including social determinants of health, that many will accept are beyond the simple control of the individual. This is not to say that other diseases do not carry stigma. This has and remains the case for diseases ranging from HIV/AIDS to depression – but, the stigma surrounding these conditions has been vastly reduced by changing the narrative of these illnesses. Today, we are more likely to think of depression (and other mental illnesses) as a problem related to “chemicals in the brain”, than something that people can pull out of with sheer motivation and will power. Perhaps changing the public narrative around obesity, from simply a matter of motivation and will power, to one that invokes the complex sociopsychobiology that really underlies this disorder, will, over time, also help reduce the stigma of obesity. Once we see obesity as something that can affect anyone (it can), for which we have no easy solutions (we don’t), and which often requires medical or surgical treatment (it does) best administered by trained and regulated health professionals (like for other diseases), we can perhaps start destigmatizing this condition and change the climate of shame and blame that people with this disease face everyday. @DrSharma Edmonton, AB
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