Your afternoon slump could signal something more than just tiredness, according to Dr Rangan Chatterjee. The bestselling author and host of the Feel Better, Live More podcast claims that the '3pm slump' is a warning sign that your glucose levels may be out of balance. A straightforward lunch swap could help prevent this energy crash.
Brits and the Afternoon Dip
Millions of Brits report experiencing the effects of the afternoon dip roughly three times a week, with tiredness, low mood, and irritability among the most frequent symptoms. For many, it also triggers a decline in productivity, snapping at loved ones, and grabbing junk food. Yet only 15% draw the link between how they feel and what they eat.
Five Key Indicators
Dr Chatterjee said the mid-afternoon slump is one of five crucial indicators that your glucose levels may be unbalanced. A poll revealed that 55% experience feeling 'hangry' at least once a week—nearly 120 episodes a year on average—but half have never thought of glucose as a factor, instead attributing it to stress and inadequate sleep.
Simple Lunch Change
According to Dr Chatterjee, lunches deficient in protein or fibre can intensify the dip. People then frequently grab a quick sugar hit, which can trigger the cycle again. To help prevent it, he recommends including a generous portion of protein at lunch to sustain you beyond the slump hour, followed by a brisk 10 to 20-minute walk after eating to help balance glucose levels naturally.
Expert Insights
Dr Chatterjee, who has partnered with Abbott's Lingo—a biosensor and app designed to help people understand their glucose levels—said: "We've normalised feeling exhausted, unfocused and irritable, but these can be early signs that the body is struggling metabolically, and that matters. 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."
He added: "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."
Brain Fog and Focus
Dips throughout the day, Chatterjee explained, can hinder brain signalling, making you feel mentally foggy and unable to concentrate. He suggested that finding yourself repeatedly going over the same email without taking it in may be a sign you should skip another caffeine hit, drink a glass of water, and have a small handful of nuts. The healthy fats provide a slower-release fuel source that can help stabilise energy.
The Role of Continuous Glucose Monitors
Dr Amy McKenzie, director of medical affairs for Abbott's Lingo, added: "We track our steps, sleep, weight and heart rate, so why not glucose? It's one of the most important indicators of how your body responds to food, stress and movement, yet for most people it's completely invisible. Making glucose visible in real time, continuous glucose monitors can turn an unseen signal into something practical and empowering—helping people understand what's really driving their energy, mood and focus, so it becomes something they can act on."
Dr Chatterjee's 5 Signs Your Glucose Levels Might Be Off Balance
- Brain fog and poor focus: Your brain is the most energy-hungry organ in your body, and glucose is its primary energy source. When glucose levels dip, the chemical messengers (neurotransmitters) that carry information between your brain cells stop working properly, leaving you with 'brain fog,' poor focus, and low mental energy.
- The daily 3pm slump: We experience a natural dip in alertness mid-afternoon as part of our circadian rhythm. However, a glucose crash can exacerbate this and prompt us to reach for quick energy or sugar, which restarts the cycle. If you feel excessively tired or need a double espresso to get through the afternoon, that's a classic sign of your body crashing after a spike.
- You're emotionally reactive ('Hangry'): When your glucose drops, your survival instinct tends to kick in, with your brain perceiving a threat and naturally releasing adrenaline and cortisol. If you find yourself snapping at your partner or colleagues when you're hungry, that's not necessarily a personality flaw—it could indicate a metabolic cry for help.
- Poor sleep and restlessness: Your body needs steady energy even while you rest. When glucose levels drop too low overnight, your system releases a surge of stress hormones (like cortisol and adrenaline) to compensate, jolting you awake and disrupting your natural sleep cycle.
- Sugar cravings: When glucose levels drop sharply, your body sends urgent signals to replenish energy fast, which often jumpstarts cravings for sugary, high-carb foods. If you find yourself consistently reaching for the biscuit tin, it may be a sign of glucose imbalance. The irony is that giving in to the craving often triggers another spike and dip, keeping you stuck in the cycle.
