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Mental Health

Excessive fatigue after eating



I am having a hard time deciding whether the postprandial sleepiness that I have been experiencing for two years now has an organic basis or if it is psychological. Basically, whenever I eat any carbohydrates like cereal, bread, oatmeal, bananas, or dairy, I feel fatigued, irritable, and confused within 15-30 minutes. I cannot think clearly and become very lethargic, which makes it very difficult to study and pay attention in class. After four or five hours, symptoms improve, but if I eat again I will become fatigued again. To alleviate symptoms, I have been trying to follow a low-carbohydrate diet, and doing so definitely decreases fatigue. The problem is that I get very constipated on this diet, and having a bowel movement becomes very onerous. I also try drinking coffee, but after a day or two the stimulant effects of caffeine diminish and I only experience diuretic effects. My TSH, fasting glucose, fasting insulin, and serum iron were all measured by my physician, and the results were normal. My BMI is around 22, so I am not overweight, and I do moderate resistance training and cardio 3-4 times a week.

The only physical cause I can think of is insulin resistance that causes me to experience reactive hypoglycemia. I am a student, so aside from my 3-5 hours of exercise per week, I am completely sedentary, which I suppose could lead to insulin resistance? Throughout school, I have also had a history of sleep curtailment, stress, and social withdrawal. I essentially became obsessed with getting all A`s and spent virtually all of my time studying (even though much of that studying wasn`t very effective). I know that these are all stressors, which can cause elevated cortisol and norepinephrine, both of which antagonize insulin. Could this theoretically have led to insulin resistance? Or do you think it is psychological? I read a paper that described how subjects with "suspected postprandial hypoglycemia" had beta-adrenergic hypersensitivity and emotional distress. I also know that carbohydrates affect serotonin levels in the brain.

If you could provide some guidance, that would be wonderful. Thank you!


I would definitely consult an endocrinologist at this point to better explore these symptoms. The timing of the symptoms to ingestion of carbs and diminution of symptoms on a low carbohydrate diet point in the direction of an insulin disorder. I do not see any evidence of a psychiatric disorder at this time from what you are describing. I would focus on a medical work-up. Take care and good luck!

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Response by:

Radu   Saveanu, MD Radu Saveanu, MD
Associate Professor
College of Medicine
The Ohio State University