A doctor has warned that hitting a 3pm fatigue slump after lunch could indicate imbalanced glucose levels. Dr Rangan Chatterjee says lunches lacking protein or fibre can worsen the mid-afternoon dip, intensifying fatigue and brain fog. However, reaching for caffeine or a quick sugar hit is not the solution.
How to Prevent the Slump
Instead, eating protein such as meat, eggs, or fish to fuel your body, followed by a brisk 10 to 20-minute post-lunch walk, helps regulate glucose levels and prevents drowsiness. Dr Chatterjee also recommends drinking a glass of water and eating a small handful of nuts, as healthy fats provide a slow-burning fuel source that stabilises energy.
"We've normalised feeling exhausted, unfocused and irritable, but these can be early signs that the body is struggling metabolically," said Dr Chatterjee, bestselling author and host of the health podcast 'Feel Better, Live More'. "Glucose is one of the most important signals in the body, shaping how we feel day to day, from our energy and mood to our focus and sleep, while also playing a role in long-term health. Prediabetes is far more common than most people realise and often develops silently. With 6.3 million people in the UK now living with it, many without knowing, there has never been a more important time to listen to what your body is telling you."
Why the 3pm Slump Happens
The 3pm slump is partly caused by our circadian rhythm, but a glucose crash can exacerbate it and prompt us to reach for a quick energy boost. Dr Chatterjee explains that when glucose levels drop sharply, the body sends urgent signals to replenish energy fast, often triggering cravings for sugary, high-carb foods. This slump makes it harder to focus because the brain is an energy-hungry organ, and glucose is its primary energy source. When glucose levels dip, neurotransmitters that carry information between brain cells stop working properly, causing poor focus and low mental energy. The irony, Dr Chatterjee adds, is that giving in to the craving often triggers another spike and dip, keeping you stuck in the cycle. If blood glucose levels remain too high, it can increase the risk of pre-diabetes.
Survey Findings
His advice comes as a survey of 2,000 adults by Abbott's Lingo, a biosensor and app designed to help people understand their glucose levels, found that more than half of those who suffer a 3pm slump experience fatigue, while about a third experience low mood and a quarter irritability. Yet, only 15% made the connection between how they feel and the food they eat. Instead, many blame factors such as stress (38%) or poor sleep (34%).
