I have repeatedly posted on the relationship between Attention Hyperactivity Deficit Disorder (ADHD) and obesity. We see a remarkable number of adults with this disorder in our bariatric clinic and, as blogged before, treating this disorder is often a key step in helping these patients manage their weight.

In kids, this disorder is often characterized by substantial hyperactivity, which would be expected to burn more calories. But what about the impact of ADHD on resting energy expenditure (REE) and the thermogenic effect of food (together accounting for about 60% if not more of the daily calories burnt)?

This question was addressed by my colleague Thomas Mueller and other researchers from the University of Alberta in a paper just published online in Eating and Weight Disorders.

Mueller and his team studied 12 pre-pubertal boys with untreated ADHD of the hyperactive-impulsive type and 12 control boys without ADHD. In addition, they examined an independent group of 60 boys with ADHD.

On average, REE was 6.5 kcal/kg fat free mass/day higher in the ADHD compared to the control group. However, there was no difference in the thermogenic effect of food between groups. Neither age nor restlessness explained the differences in REE.

Despite the higher REE (and likely higher activity energy expenditiure due to the innate restlessness that comes with this condition), boys with ADHD had similar BMI levels compared to non-ADHD reference groups.

Thus, this paper shows that despite a notably greater energy expenditure, ADHD kids are not generally leaner, clearly suggesting that they manage to make up for their greater energy needs through higher caloric intake.

One may well speculate that as these kids become older and their REEs (and activity expenditures?) decrease, persistence of a higher caloric intake than their non-ADHD peers may well make them more prone to obesity as adults.

How and why REE is elevated in ADHD clearly deserves further study. I’d certainly appreciate hearing from any of my readers, who have experience with the ingestive behaviour of ADHD kids.

AMS
Burlington, Ontario

While I am taking a brief break from clinics and other obligations (including daily blog posts), I will be reposting past articles, which I still believe to be relevant but may have escaped the attention of the 100s of new readers who have signed up in the past months.

The following was first posted on 04/01/08 (For more recent posts on this topic click here)

There are over 50 recent publications in PubMed on the possible link between Attention Deficit Disorder (ADD) and obesity. In my own anecdotal experience I continue to be surprised on how many patients presenting with obesity have clear signs of this disorder.

They are usually the patients who show up late for appointments because they locked their keys in their cars, did not fill the last prescription for their metformin because they lost it, started filling out food records but never got past the first day, used their new bike only once because they never got around to fixing the flat tire from their first ride, take a packed lunch to work but forget to eat it, enthusiastically start a new diet but lose interest three days later because weight loss is too slow - I could go on forever - you probably get the picture.

In my practice I have come to recognize that ADD is probably one of the most common and frustrating barriers to obesity management. By definition, individuals with ADD lack the ability to plan ahead and to follow through on their plans, easily lose interest, and are constantly sabotaged by their impulsiveness when it comes to making healthy choices.

There is now evidence to support the notion that alterations in the dopaminergic reward system may be common to both ADD and hedonistic hyperphagia. Not surprisingly there is some work showing that methylphenidate (ritalin) can sometimes reduce cravings for sweet and fatty foods.

It does not surprise me that someone with ADD is probably more prone to “mindless eating” and thus more likely to gain weight than someone with proper impulse control.

One of the most remarkable cases I recall was a patient, who after being started on ritalin, at his next visit for the first time brought in and proudly presented meticulously completed food records (he was also a couple of pounds lighter).

In medicine it is always easiest to blame the patient - not motivated, not interested, not focused, not following instructions, not compliant, not adherent, etc.

Recognizing that this behavior may be due to ADD and providing proper treatment for this condition may in these cases be the first step to obesity management.

AMS
Edmonton, Alberta

In response to yesterday’s post on ADHD and obesity, I was made aware of two recent studies, both relevant to this topic.

In the first, A psycho-genetic study by Caroline Davis and colleagues from York University, Toronto, Ontario, Canada, published in the Journal of Psychiatric Research, the researchers examined whether ADHD symptoms were more pronounced in adults with symptoms of binge eating disorder (BE) than in their non-binging obese counterparts, and whether the links were stronger with inattentive vs impulsive/hyperactive symptoms. They also assessed the role of the dopamine D3 receptor in ADHD symptoms since the DRD3 gene has been associated with impulsivity and drug addiction - both relevant features of ADHD.

In the study that involved 60 cases and 120 controls (60 obese and 60 normal weight), childhood and adults ADHD symptoms were assessed and genotying was performed.

While all of the four ADHD symptom scales were significantly elevated in the BE and obese groups compared to the normal weight group, bearers of three DRD3 genotypes had significantly elevated scores on the hyperactive/impulsive symptom scale.

These results suggest that symptoms of ADHD are more common in obese individuals (irrespective of BED status) and that the D3 receptor may play a role in the manifestation of the hyperactive/impulsive symptoms of ADHD.

In another study, published in this month’s issue of OBESITY by Lance Levy and colleagues from the Nutritional Disorders Clinic, also in Toronto, Ontario, Canada, they describe their success in treating refractory obesity in severely obese adults following the management of newly diagnosed attention deficit hyperactivity disorder.

78 subjects out of 242 consecutively referred severely obese, weight loss refractory individuals were diagnosed as having ADHD, of which 65 received ADHD treatment and 13 remained as controls.

After an average of 466 days of continuous ADHD pharmacotherapy, weight change in treated subjects was -12% of initial weight versus a 3% weight gain in controls.

This study not only confirms that ADHD is a highly prevalent condition in severely obese patients, but that the treatment of ADHD is associated with significant long-term weight loss in individuals with a lengthy history of weight loss failure.

Levy suggests, as I did in earlier postings on this topic, that ADHD should be considered as a primary cause of weight loss failure in obese patients.

As he points out, this finding may also be important for patients seeking obesity surgery, as surgical patients with unmanaged ADHD may display poor compliance with diet and supplement requirements.

AMS
Edmonton, Alberta

p.s. Caroline Davis will be presenting at the upcoming 1st National Obesity Summit, Kananaskis, Alberta, May 7-10, hosted by the Canadian Obesity Network

In my clinical practice I remain impressed by the surprisingly high incidence of attention deficit hyperactivity disorder (ADHD) in my obese patients. Many have had symptoms all their lives, many have kids diagnosed and treated for ADHD, but have never considered that they may have this condition themselves.

Long-time readers of this blog will recall several previous postings on this issue - there is little doubt that ADHD is a major handicap in dealing with a weight problem. Lack of impulse control, difficulty planning and following through on lifestyle changes, compliance problems - all make it difficult for someone with ADHD to tackle their weight problem.

But how close is the relationship between ADHD and obesity in the general population?

Based on previous observations that while ADHD affects ~2.9-4.7% of US adults, this condition is reported to be present in 26-61% of patients seeking weight loss treatment, Sherry Pagoto and colleagues from the University of Massachusetts, MA, USA, revisited this issue in a paper published in this month’s issue of OBESITY.

Using cross-sectional data from the Collaborative Psychiatric Epidemiology Surveys, which includes data from 6,735 US residents (63.9% white; 51.6% female) aged 18-44 years, a retrospective assessment of childhood ADHD and a self-report assessment of adult ADHD were administered.

The prevalence of overweight and obesity was 33.9 and 29.4%, respectively, among adults with ADHD, and 28.8 and 21.6%, respectively, among persons with no history of ADHD. Thus, adult ADHD was associated with a 58% greater likelihood of overweight and 81% greater likelihood of obesity.

Further analyses suggested that binge eating disorder (BED), but not depression, partially mediates the associations between ADHD and excess weight. This is not surprising, given that poor impulse control is likely to affect binge-eating behaviour.

The study underlines what I have long proposed: assessment for ADHD should be part of routine work up for obesity and weight-related health problems. When present, ADHD can pose a major barrier to obesity management and should be addressed by CBT and/or medications.

AMS
Edmonton, Alberta

Humans are omnivores and apparently our hunter-gatherer ancestors ate an extraordinary range of plant and animal foods.

The advent of culinary skills and use of spices and seasonings further enhanced the variety, taste, flavour, appearance, texture and consistency of foods.

Today, the apparently limitless choice of foods in our supermarkets, restaurants and homes is a sure sign of the importance we place on variety and variation when it comes to eating.

When trying to manage your weight, however, variety may be your downfall.

This at least is the gist of a recent study by Ramona Guerrieri and colleagues from the Department of Experimental Psychology, Maastricht University, in The Netherlands, who examined the interaction between impulsivity and a varied food environment and its influence on on food intake and overweight, published in the International Journal of Obesity.

The study is based on two observations:

1) Our current food environment offers a large variety of cheap and easily available sweet and fatty foods

and

2) Impulsive people may be reward sensitive and are generally less successful at inhibiting prepotent responses (i.e. a response that is or has been previously associated with positive reinforcement)

Using a rather complicated experimental design masquerading as a taste test, Guerrieri and colleagues studied 78 healthy primary school children (age: 8-10 years) regarding two aspects of impulsivity: reward sensitivity and deficient response inhibition.

The kids were studied in two groups: one was offered rather monotonous foods; the other was offered foods varied in colour, form, taste and texture.

As expected, reward sensitivity interacted with variety. In the “monotony group” there was no difference in food intake between the less and more reward-sensitive children (183 kcal+/-23 s.d. versus 180 kcal+/-21 s.d.).

However, in the “variety group” the more reward-sensitive children ate almost 70% more calories than the less reward-sensitive children (237 kcal+/-30 s.d. versus 141 kcal+/-19 s.d.).

While reward sensitivity in itself was not linked to overweight, deficient response inhibition (a measure of impulsivity) was.

Clearly, the kids with poor impulse control were handicapped when it came to dealing with variety.

Why is this important?

What the data suggest is that kids (and adults?) who have poor impulse control are more likely to overeat when faced with variety. Therefore, the incredible variety and choices of food that we have available to us, may indeed be a major factor in the problem of overeating.

As blogged previously, attention deficit disorders (ADD) are surprisingly common in obese children and adults - in our currently environment, this increased impulsivity may be an important factor contributing to their weight gain.

If your problem is impulse control - the less choices you give yourself the better.

AMS
Edmonton, Alberta