“Why am I gaining weight?” This is a common complaint, often with no ultimately satisfactory answer or solution. Still, diagnostics should precede attempts at therapeutics.
First Step (obviously) — Compare current weight to past ones. I’m only satisfied with recorded data (not what someone recalls from 6 months ago). As such, I virtually only count on the office scale. I’m not convinced it’s more accurate than others, but at least it’s consistent and charted.
I don’t care what clothes the patient is wearing, nor if weights are taken with or without shoes, because the differences are minimal, and I’m looking for major trends (not just a couple of pounds). We do, however, remove large bulky jackets and reinforced boots.
If it’s a new patient without prior weights, I check belt buckle notches as a form of objective documentation. In the absence of a belt, inquiring about changes in clothing size offers some validation. I’ve seen many patients complaining of “weight gain” whose charted weights reflect no change, or even loss!
Still, with a new patient and no data of my own, it’d be unkind to doubt their perception. If they’re not obese, offer to follow their weights every month or two. If obese, and they want to lose, you’ll certainly follow weights as part of weight-loss management plan. Similarly, with a regular patient who’s obese, even if weights have been documented as stable, maybe this is their transition from pre-contemplative to contemplative, and they’re ripe for engagement
If the patient has been followed in the past, and you can document the absence of weight gain, reassurance should be well-accepted. After all, they were afraid they’re getting fat / fatter, and in fact they’re not. But if they’re not reassured, and appear preoccupied, explore possible Bulimia, especially if the patient is not obese.
The sine qua non of Bulimia are Binges — eating the equivalent of 2 normal meals within 2 hours. However, patients may not be forthcoming, especially if you haven’t an established relationship with them. It may be more productive to inquire about loss of control when it comes to food, and whether food dominates their life.
There are two Screening Tools for Eating Disorders, with decent accuracy. Physical exam may include tachycardia, dry skin, and signs of self-induced vomiting (puffy cheeks, loss of tooth enamel, irritative rashes on dorsum of hands). Bulimia can be life-threatening if it includes suicidality.
Moving on to bona fide documented weight gain.
Start by examining the ankle malleoli for edema. If present, we’re dealing with a whole different issue. See our past posting for work-up of Edema.
Digression — Sometimes a patient presenting for “weight gain” really means their abdominal girth is increasing. This can occur with or without weight gain, or even with weight loss (ominous). The mnemonic for differential diagnosis of a distended abdomen is “6 F’s”:
- Fat
- Fluid (ascites)
- Fetus (pregnant)
- Feces (constipation, impaction)
- Flatus (bowel obstruction)
- Fatal Masses (abdominal tumors, malignant or benign)
This isn’t hard to sort out. Fat is the diagnosis of exclusion. Fetus can be determined by history, with pregnancy test if necessary. Feces causing abdominal distention will be obvious from history, in which case a rectal exam will identify impaction.
Flatus (air in abdomen, not farting), usually only an issue when distention is acute, is found by percussion (diffuse tympani beyond the normal resonance). A word about auscultation — “hyperactive bowel sounds” is defined by hearing “tinkles” or “rushes,” not just lots of gurgles. It means bowel obstruction (easily seen on abdominal plain films, flat plate (KUB) + upright, as dilated bowel loops with air-fluid levels.
To rule out Fluid (ascites), seek other signs of portal hypertension (click link for stigmata of cirrhosis and how to find shifting dullness on abdominal exam). As for Fatal Masses (tumors), palpate as best you can. Pay special attention to the periumbilical area. Women may warrant a pelvic exam for abdominal distention; benign ovarian masses can weigh up to 100 lbs. [!!!].
Finally, back to “Weight Gain” — Once you’ve documented weight gain, and determined it’s not due to edema, give some thought to possible organic causes. There aren’t many; they include the following:
** Hypothyroidism: A TSH is a simple test for someone whose weight increases while insisting they “hardly eat.” It’s invariably normal, but patients are happy you drew it.
** Cushing’s Syndrome: Very rare. Characterized by abdominal obesity with thin extremities, purple striae, moon face, buffalo hump. Patients are usually hyperglycemic, maybe hypertensive too. Order a 24-hr. urine for cortisol, but only if there’s decent clinical suspicion.
** Growth Hormone Deficiency: Can cause weight gain. In children, work-up is done for those presenting with short stature. In adults, the condition is very rare, and presents very vaguely. Obviously it should be explored for persons with known pituitary disease. If the TSH is low & Free T4 also, you’ve found a case of Central Hypothyroidism [rare], which should generate additional pituitary hormone testing (GH, FSH, LH, and ACTH).
Otherwise, you might wonder about Growth Hormone Deficiency in the adult with weight gain causing central obesity (thin extremities, loss of lean muscle mass), plus a variety of non-specific complaints like low energy, decreased libido, poor sleep, & mood symptoms. Such patients who gain weight invariably get diagnosed & treated for a primary mood disorder.
Low levels of Insulin-like Growth Factor make the diagnosis, but many affected adults will test normal. Endocrinology can do a variety of provocative tests, but might feel overwhelmed (and ungrateful) if we begin to refer all our depressed patients who are gaining weight. I’ve never entertained the diagnosis; might consider it in a patient with objective central obesity (i.e. real thin extremities compared to abdominal obesity), and very abnormal lipids (↑↑↑ LDL, ↑↑↑ TGs, ↓↓↓ HDL).
** Medications: Culprits include newer antipsychotics, lithium, tricyclics, paroxetine, mirtazepine, valproic acid, carbamazepine, gabapentin, beta-blockers, sulfonylureas, and insulin.
Enough. Essentially what we’ve done for the patient with documented weight gain is:
- Determined the weight isn’t due to edema
- Clarified we’re addressing increase in pounds, not abdominal girth
- Ruled out hypothyroidism as cause
- Found no reason to suspect an obscure etiology
So we’re left with what we’ve suspected [known] all along, our patient is simply getting fatter. The reason is a combination of increased intake, less energy expenditure, and genetics. For those over 30, you can say there’s data that people in general gain weight then (patients feel better when you blame it on age).
You can, of course, take a diet & exercise history to identify any culprit patterns which might be amenable to change. Ultimately, people who want to lose weight will have to decrease calories & increase exercise. I don’t have much experience in this, since we have nutritionists available for referrals. I did read somewhere that if somebody with food allergies is asked to keep a food diary, & they bring in a completely detailed list, you’ve diagnosed obsessive-compulsive disorder as the cause of their symptoms.
Some inquiries into possible reasons for weight gain might be useful:
- Recent Smoking Cessation: a common cause, attenuates over 6 months (but won’t usually reverse). Obesity is much less dangerous than continued smoking.
- Sleep Deprivation: hormonal responses may be related to weight increase, & may counteract dietary changes. Usually hard to modify, but knowledge of relationship may decrease patient frustration, even motivate some to pursue other lifestyle changes.
- Nighttime Eating: A baddie. Find some way to avoid.
- Rapid Eating: If endorsed by patient, suggest they make a conscious effort to 1) chew each mouthful for extra time; and 2) compulsively place the fork/spoon on table until swallowing [to prevent shoveling].
Obesity is obviously common, extremes are serious, and it is now (2013) accepted by medical authorities [insurers] as an “illness.” Treatment is difficult. It should generate comparable compassion, especially given the societal disdain. We’ve dealt merely with the little diagnostics at play.
So this was brief. You can go back to exercise now [or to nibbling].
DiagnosisDude 