- A nutrition researcher says blood-sugar crashes were causing her afternoon fatigue and moodiness.
- Switching to a high-protein breakfast with healthy fats and fiber has given her more energy, she says.
- Her research suggests about 25% of people could benefit from similar healthy habits.
A nutrition researcher says switching up her breakfast routine has helped her beat the 4 o'clock crash.
Sarah Berry, a professor at King's College in London who's also the chief scientist at the health-science company Zoe, had been struggling with afternoon fatigue, moodiness, and cravings.
"Every day at 4 o'clock, I used to get grumpy walking my kids home from school and feel a bit dizzy and then go and literally gorge on food because I felt so funny," she told Business Insider.
Despite more than two decades working in nutrition research, Berry hadn't really changed her eating habits.
Then she tried a continuous glucose monitor, a now-trendy device that offers real-time updates on blood-sugar levels in response to food, exercise, and other habits.
Berry found out that her blood sugar was crashing every afternoon when she'd had a high-carb breakfast, which helped explain the exhaustion she'd been feeling.
With a little planning ahead, she's been able to adjust her habits for more-stable blood sugar and better energy throughout the day, finding habits that work best for her body, routine, and priorities.
"This guidance that's kind of a one-size-fits-all approach doesn't necessarily optimize for the best diet at an individual level," Berry said.
Blood-sugar spikes and dips may mess with your energy
Berry said she's what's known in Zoe studies as a "dipper," prone to blood-sugar crashes that can leave her feeling foggy and wanting to snack in search of more energy.
Zoe research suggests that about 25% to 30% of people fall into this category, tending to experience drops in blood sugar below baseline several hours after eating a lot of carbs.
Berry's personal experience and the Zoe data indicate that low blood-sugar levels can make people more likely to overeat and feel less alert and energized than they might otherwise.
She found in her research that after a high-carb meal, so-called dippers craved another meal much sooner than non-dippers and tended to eat about 100 calories more at the next meal and about 300 calories more a day in an effort to stave off the slump.
"We know it actually makes you in the moment feel rubbish," Berry said.
A high-protein breakfast can provide lasting fuel
Prior to checking out her blood-sugar response, Berry might have had a pastry or white toast for breakfast. But she found that overloading on refined carbs and sugars led to a "rollercoaster" effect of dips and spikes, leading to more cravings later on.
Instead, she's switched to Greek yogurt loaded with nuts and seeds, a breakfast that's full of protein, healthy fats, and some fiber, all of which help to slow digestion for fewer blood-sugar fluctuations.
"It keeps me full for a long time, and it sets me off on a nice path of gentle undulating hills of glucose. You don't want these mountains and these ravines, for example," Berry said.
She still makes time to enjoy food
Berry hasn't cut out carbs or treats completely, and she said it's not realistic to expect blood sugar to be perfectly flat or balanced throughout the day.
"An increase in circulating blood sugar is a normal physiological response to eating carbohydrate," she said. "Our bodies are made to be able to handle changes in circulations of blood glucose."
The key is moderation and to find healthy ways to enjoy carbs and other foods without extremes.
"If a food is too healthy to be enjoyed, it's just not healthy at all," she said.
That also means making compromises and making choices that work best for your lifestyle. For instance, there's some evidence that eating late at night can prompt a bigger blood-sugar response, but Berry said it's worth it to have dinner with her family.
"We have to remember food is part of our culture, our emotions, our social setting. I want to sit down in the evening with my family," she said. "I know it's eating late, but I would rather be with my family because that's more important."
