From the Guidelines
Postprandial fatigue is primarily caused by the physiological processes of digestion and nutrient absorption, which can lead to a temporary energy deficit, reduced blood flow to the brain, and the release of neurotransmitters that promote relaxation and sleepiness, as seen in dumping syndrome after esophageal, gastric, or bariatric surgery 1.
Causes of Postprandial Fatigue
- Digestion and nutrient absorption: The body redirects blood flow to the digestive system, reducing blood flow to the brain and contributing to feelings of tiredness.
- Release of insulin: In response to rising blood sugar levels, insulin facilitates the entry of tryptophan into the brain, which is then converted to serotonin and melatonin, promoting relaxation and sleepiness.
- Temporary energy deficit: The digestive process requires energy, creating a temporary energy deficit that can manifest as fatigue.
- Dumping syndrome: A condition that can occur after esophageal, gastric, or bariatric surgery, characterized by early and late dumping symptoms, including profound fatigue after meal ingestion, hypotension, and a sympathetic nervous-system response 1.
Management of Postprandial Fatigue
- Eating smaller, more frequent meals: To reduce the load on the digestive system and prevent rapid blood sugar spikes.
- Reducing carbohydrate intake: Especially refined carbohydrates, which can cause rapid blood sugar spikes followed by crashes.
- Including protein with meals: To stabilize blood sugar and provide a feeling of fullness.
- Staying hydrated: To help with digestion and prevent dehydration.
- Taking a short walk after eating: To improve circulation and digestion.
Special Considerations
- Dumping syndrome: Patients who have undergone esophageal, gastric, or bariatric surgery should be aware of the risk of dumping syndrome and take steps to manage their symptoms, including eating smaller meals, avoiding high-carbohydrate foods, and staying hydrated 1.
- Diabetes management: Patients with diabetes should work with their healthcare provider to develop a meal plan that takes into account their medication regimen and blood sugar levels, and to learn how to count carbohydrates or use another meal planning approach to quantify carbohydrate intake 1.
From the Research
Causes of Postprandial Fatigue
The causes of postprandial fatigue are complex and multifaceted. Several studies have investigated the relationship between dietary intake and fatigue, with some suggesting that certain nutrients and meal compositions may contribute to feelings of tiredness after eating.
- Emotional Eating and Stress Response: A study published in 2014 found that emotional eating and a decrease in food intake under mental stress were associated with fatigue in healthy young adults 2.
- Dietary Intake and MS-Related Fatigue: Research on multiple sclerosis (MS) patients has shown that dietary intake may play a role in managing MS-related fatigue, with some studies suggesting that adequate magnesium and folate intake may help reduce fatigue 3.
- Meal Composition and Fatigue: Studies have examined the effects of different meal compositions on postprandial fatigue, with one study finding that a pure carbohydrate meal led to increased subjective feelings of fatigue and slower reaction times, while a pure fat meal was associated with aspects of central fatigue 4.
- Age and Fatigue: Age may also be a factor in postprandial fatigue, with older adults potentially being more vulnerable to fatigue-induced changes in tongue strength and swallowing function 5.
- Hormonal Responses and Fatigue: The release of certain hormones, such as cholecystokinin (CCK), may also contribute to postprandial fatigue, with one study finding that a high-fat-low-carbohydrate meal led to increased CCK concentrations and greater ratings of fatigue 6.
Key Findings
Key findings from these studies suggest that:
- Emotional eating and stress response may contribute to fatigue in healthy young adults
- Dietary intake, including adequate magnesium and folate, may help manage MS-related fatigue
- Meal composition, including carbohydrate and fat content, may influence postprandial fatigue
- Age may affect susceptibility to fatigue-induced changes in tongue strength and swallowing function
- Hormonal responses, such as the release of CCK, may play a role in postprandial fatigue