NBME 22 Calorie consumption that exceeds energy expenditure (NBME Answers)

NBME 22 Answers

nbme22/Block 4/Question#48 (reveal difficulty score)
An 8-year-old boy is brought to the physician ...
Calorie consumption that exceeds energy expenditure 🔍 / 📺 / 🌳 / 📖
tags: nutrition

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submitted by ∗aesalmon(95)

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I feel dumb for asking but can someone explain this? If his parents are of close to normal BMI and are concerned about his weight why would they be allowing his calorie consumption to exceed his energy expenditure? ( AKA letting the kid eat too much and not exercise enough)

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meningitis That's a modern day mystery. +23

drdoom The prompt is only asking "what's the likely cause of obesity?" It's not that they're "allowing" him to eat more than exercise. (Few parents can monitor their kids that closely!) The prompt is only asking what's the most likely explanation for his 95th percentile weight and BMI (given that he otherwise appears normal); in the United States, the most likely explanation is eating way more than you expend. +2

niboonsh aka 'merica #firstworldproblems +5

makinallkindzofgainz If you are obese, it's because you have consumed calories in excess of your energy expenditure, end of story. (there are factors that affect your energy expenditure, but the simple statement is 100% true, unless you want to argue against the laws of thermodynamics). A is the only correct answer. +1

tulsigabbard This answer hit too close to home. +6

castlblack I think the reason they point out the average weight of the parents is because leptin disorders are inherited. It helps you eliminate that answer choice. +2

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submitted by rogeliogs(12)

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My approach to this question was more just focusing in the info they are giving. None of the other option makes sense because there is not evidence to talk about them. I was very tempted to pick the "decrease leptin production" but I remembered Dr Goljan saying "Think simple, think cheap, they are not trying to trick you." So, chubby parents = chubby kids.

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almondbreeze thought his words on "think cheap" had to do with treatments - i.e. exercise +

alimd Yes they are. There are so many trick questions +1

skuutnasty I chose leptin deficiency cuz I was tryna get fancy with it. For anyone who is interested, however... according to UpToDate: "Most people with obesity do not have any abnormalities in the leptin gene, their serum leptin concentrations are high reflecting their increased fat mass..." Peace +6

sunnyside @skuutnasty should've just let me feel fancy, now i feel stupid :( +

FA 2019 pg. 327 on leptin + Satietyhormone.Producedbyadiposetissue.Mutationofleptingene- congenitalobesity.Sleep deprivation or starvation - I leptin production. Leptin keeps you thin. Acts on ventromedial area of hypothalamus (satiety center) to I appetite.

I picked leptin too. However, the q asks for the 'most likely explanation' for his obesity.

+1/- almondbreeze(110)

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submitted by rongloz(7)

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I would like to include here that it can not be B (Decreased leptin production) because leptin levels increase in obesity. Leptin is secreted by adipocytes, which become significant in obesity. High levels of leptin may also desensitize the satiety centers in the hypothalamus, which is why many obese people have trouble limiting their food intake.

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madamestep Very true! Also leptin causes changes in appetite. So even if leptin is low, your reason for obesity is still more calories in than out. +

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submitted by jotajota94(14)

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I think the key to understanding this question is that the boy has above average height. Leptin stimulates the release of GH (https://www.ncbi.nlm.nih.gov/pubmed/12122085) Children with Cushing syndrome have short stature https://www.ncbi.nlm.nih.gov/pubmed/16675933) insulin inhibits GH secretion https://www.ncbi.nlm.nih.gov/pmc/articles/PMC425166/) I think that both a high caloric diet in fats and glucose can make you fat so you can eliminate those answer choices.

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