Postprandial Fatigue: Is It Normal To Need A Nap After Lunch?

July 10, 2020

We get a lot of questions from our clients about postprandial fatigue. Never heard of it? Well you’ve certainly familiar with the term “food coma” - and perhaps with the experience of being in one. What causes this phenomenon and why does it affect some people more than others? Is it normal to need a nap after lunch? 

On this podcast I’m joined by NBT Scientific Director Megan Hall to talk about postprandial fatigue - the sleepiness, difficulty focusing, and even dizziness or nausea that strikes after consuming a meal. Megan talks about some of the biological processes behind the need for a post-meal snooze, and when to suspect a deeper pathology. She also offers practical tips to help you resolve your own postprandial fatigue.

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Here’s the outline of this interview with Megan Hall:

[00:04:25] Common symptoms of postprandial fatigue.

[00:05:46] Reactive hypoglycemia; Study: Johnson, Debra D., Kay E. Dorr, and Wendell M. Swenson. "Reactive hypoglycemia." JAMA 243.11 (1980): 1151-1155. 

[00:06:35] Diagnosing reactive hypoglycemia; Study: CHALEW, STUART, et al. "Diagnosis of reactive hypoglycemia: pitfalls in the use of the oral glucose tolerance test." Southern Medical Journal 79.3 (1986): 285-287.

[00:09:00] Symptoms and causes of hypoglycemia.

[00:09:37] Increased insulin sensitivity; Studies: 1. Brun, J. F., et al. "Increased insulin sensitivity and basal insulin effectiveness in postprandial reactive hypoglycaemia." Acta Diabetologica 33.1 (1996): 1-6; 2. Vexiau, P., B. Legoff, and G. Cathelineau. "Insulin and cortisol secretion during OGTT in patients with reactive hypoglycaemia with or without clinical symptoms." Hormone and metabolic research 15.09 (1983): 419-421.

[00:09:47] Hypocortisolism; Studies: 1. Meyer, Gesine, et al. "Nocturnal hypoglycemia identified by a continuous glucose monitoring system in patients with primary adrenal insufficiency (Addison's disease)." Diabetes Technology & Therapeutics 14.5 (2012): 386-388; 2. Christiansen, Jens Juel, et al. "Effects of cortisol on carbohydrate, lipid, and protein metabolism: studies of acute cortisol withdrawal in adrenocortical failure." The Journal of Clinical Endocrinology & Metabolism 92.9 (2007): 3553-3559.

[00:10:05] Hypothyroidism; Studies: 1. Kalra, Sanjay, Ambika Gopalakrishnan Unnikrishnan, and Rakesh Sahay. "The hypoglycemic side of hypothyroidism." Indian Journal of Endocrinology and Metabolism 18.1 (2014): 1; 2. Yadav, Tek Chand, et al. "Recurrent hypoglycemia: An unusual finding of hypothyroidism." Thyroid Research and Practice 14.3 (2017): 127.

[00:10:53] What to do about hypoglycemia.

[00:13:09] Accelerated gastric emptying.

[00:16:20] Reactive hypoglycemia after exercise.

[00:18:51] Postprandial hyperglycemia; Study: Gerich, John E. "Clinical significance, pathogenesis, and management of postprandial hyperglycemia." Archives of internal medicine 163.11 (2003): 1306-1316.

[00:20:38] Problems associated with hyperglycemia; Studies: 1. Ceriello, Antonio, et al. "Meal-induced oxidative stress and low-density lipoprotein oxidation in diabetes: the possible role of hyperglycemia." Metabolism 48.12 (1999): 1503-1508; 2. Ceriello, Antonio, et al. "Meal-generated oxidative stress in type 2 diabetic patients." Diabetes care 21.9 (1998): 1529-1533; 3. Cavalot, F. "Do data in the literature indicate that glycaemic variability is a clinical problem? Glycaemic variability and vascular complications of diabetes." Diabetes, Obesity and Metabolism 15.s2 (2013): 3-8; 4. Ceriello, Antonio, et al. "Evidence for an independent and cumulative effect of postprandial hypertriglyceridemia and hyperglycemia on endothelial dysfunction and oxidative stress generation: effects of short-and long-term simvastatin treatment." Circulation 106.10 (2002): 1211-1218; 5. Tibaldi, Joseph. "Importance of postprandial glucose levels as a target for glycemic control in type 2 diabetes." Southern medical journal 102.1 (2009): 60-66.

[00:21:24] Insulin resistance.

[00:21:39] Video: PAH 2016 - A systems analysis approach to insulin resistance, with Dr. Tommy Wood.

[00:23:02] What to do: Look at diet; 1. Krebs, Jeremy D., et al. "Improvements in glucose metabolism and insulin sensitivity with a low-carbohydrate diet in obese patients with type 2 diabetes." Journal of the American College of Nutrition 32.1 (2013): 11-17; 2. Lin, Po-Ju, and Katarina T. Borer. "Third exposure to a reduced carbohydrate meal lowers evening postprandial insulin and GIP responses and HOMA-IR estimate of insulin resistance." PloS one 11.10 (2016): e0165378; 3. MacDonald, Ian A. "A review of recent evidence relating to sugars, insulin resistance and diabetes." European journal of nutrition 55.2 (2016): 17-23; 4. Bradley, Una, et al. "Low-fat versus low-carbohydrate weight reduction diets: effects on weight loss, insulin resistance, and cardiovascular risk: a randomized control trial." Diabetes 58.12 (2009): 2741-2748.

[00:28:46] Mediterranean diet; Study: Guasch-Ferré, Marta, et al. "Dietary polyphenols, Mediterranean diet, prediabetes, and type 2 diabetes: a narrative review of the evidence." Oxidative Medicine and Cellular Longevity 2017 (2017).

[00:29:56] Endotoxemia and insulin resistance 1. Moreira, AP Boroni, and R. de Cássia Gonçalves Alfenas. "The influence of endotoxemia on the molecular mechanisms of insulin resistance." Nutrición hospitalaria 27.2 (2012): 382-390; 2. Cani, Patrice D., et al. "Metabolic endotoxemia initiates obesity and insulin resistance." Diabetes 56.7 (2007): 1761-1772.

[00:30:24] Megan's outline for this podcast. 

[00:31:19] When fatigue after a meal might be normal.

[00:33:08] Article: Why a pandemic flu shot caused narcolepsy.

[00:33:49] Both high fat and high carb meals can cause sleepiness; Study: Wells, Anita S., et al. "Effects of meals on objective and subjective measures of daytime sleepiness." Journal of applied physiology 84.2 (1998): 507-515.

[00:33:56] Intestinal stimulation can cause sleepiness; Kukorelli, Tibor, and Gábor Juhász. "Electroencephalographic synchronization induced by stimulation of small intestine and splanchnic nerve in cats." Electroencephalography and clinical neurophysiology 41.5 (1976): 491-500.

[00:34:20] Sleepiness after eating vs. just chewing; Study: MJ Harnish, SR Greenleaf, WC Orr, “A comparison of feeding to cephalic stimulation on postprandial sleepiness.” Physiology & behavior 64.1 (1998):93-96.

[00:34:38] Cholecystokinin (CCK) may affect the alert centers in the brain; Study: Wells, Anita S., et al. "Influences of fat and carbohydrate on postprandial sleepiness, mood, and hormones." Physiology & behavior 61.5 (1997): 679-686.

[00:37:13] Thermogenesis; Study: Zammit, Gary K., et al. "Postprandial sleep and thermogenesis in normal men." Physiology & behavior 52.2 (1992): 251-259.

[00:37:40] Summary: How to fix the problem.

[00:38:43] Nutrisense for continuous glucose monitoring (CGM).

[00:46:29] Timing your walk with glucose peak; Study: Reynolds, Andrew N., and Bernard J. Venn. "The timing of activity after eating affects the glycaemic response of healthy adults: a randomised controlled trial." nutrients 10.11 (2018): 1743.

[00:51:01] Support NBT on Patreon to access the forum.