Thyroid UK

exhaustion after eating

Does any body know why eating makes my energy crash at midday? As soon as I've eaten lunch I just have to take to bed and sleep for the rest of the day. Eating makes me unbelievably exhausted. I can almost feel my heart slowing down, it feels like eating makes it struggle to keep going. My basal pulse is 59 - 60 at the moment and basal temperature is between 35.5 and 36.5 so my metabolism is very slow at the moment. I was only diagnosed two weeks ago with under active thyroid. Does anyone else have extreme exhaustion after eating?

3 Replies

Something we take for granted like digestion of food, actually requires a lot of resources. When you're thyroid levels are wonky, energy management is a real problem in every respect.

It might help to eat low GI foods so that you don't get blood sugar surges. Low carbohydrate diets seem to work well for many hypOthyroid people, not only for weight loss but for energy levels too.


It may be that it's not so much the eating that's making you exhausted but the time of day. You may have thyroid levels that are ok for the morning but not the afternoon (TSH levels change throughout the day). You might find things change as your TSH levels drop.


This is an older post but I found out the answer to this question a long time ago and thought I'd put it here for those who may still be looking for an answer:

It is your blood sugar that makes you so exhausted after you eat. This is a somewhat common hypothyroid problem.

It is known as "Reactive Hypoglycemia."

Before I even knew what it was called, I corrected my problem by eating much smaller meals and never going without sustenance longer than 2-3 hours. I used orange juice laced with the finest unrefined sea salt in between meals to keep my blood sugar from fluctuating. Just a few sips was all I needed to keep my blood sugar levels intact. Then when I ate a larger meal, my body became much less reactive to carbohydrates. I also increased my fat and protein intake. Soon there was no reaction at all and what had previously happened to me for years (crashing with exhaustion after eating) was completely gone.

"This condition, called reactive hypoglycemia, occurs when the body secretes excess insulin in response to a high carbohydrate meal – causing blood sugar levels to drop below normal." (Chris Kresser Jul 23, 2010)


You may also like...