Research suggests that kiwis may support sleep, energy, and immune function when eaten regularly over time. However, when it comes to the best timing to maximize these benefits, the evidence isn’t clear-cut.
Researchers don’t know for sure the best time to eat kiwi to improve sleep—existing research has focused only on how eating the fruit before bed affects sleep outcomes. Those studies are small and typically involve people without chronic sleep disorders, said Giana DiMaria, MS, RD, CNSC, CCMS, a clinical registered dietitian specialist and instructor of medicine at Westchester Medical Center and New York Medical College School of Medicine.
Still, the evidence suggests that eating kiwi before bed may improve sleep. Specifically, several studies have found that eating two kiwis an hour before bedtime reduces the time it takes to fall asleep, decreases nighttime awakenings, and boosts overall sleep duration and quality.
Kiwis may support better sleep because they contain compounds linked to improved shuteye: melatonin, serotonin, fiber, folate, and antioxidants.
But “it is unknown if consuming the fruit earlier in the day could also support sleep patterns to the same degree,” Karen Lindsay, PhD, RDN, a registered dietitian nutritionist at the Susan Samueli Integrative Health Institute at UC Irvine Health, told Health.
Similarly, it’s unclear whether there’s a “best” time to eat kiwis for energy.
Limited research suggests that daily kiwi consumption may support “enhanced mood and vitality,” Lindsay said. Kiwi is also rich in vitamin C—one fruit contains 82 milligrams, more than the recommended daily allowance for adult women—and has been shown to improve constipation and other gastrointestinal issues, both of which could indirectly influence energy levels.
Notably, however, studies examining kiwi and energy do not specify the time of day the fruit was consumed, Lindsay pointed out.
Because kiwi is rich in vitamin C, which helps the immune system function properly, eating it may indirectly support your body’s ability to protect against disease (though vitamin C cannot shield you from germs or guarantee you won’t get sick).
But there’s no evidence that timing of consumption matters when it comes to immunity. “It is unlikely that the time of day will be relevant,” Lindsay said.
While there isn’t strong evidence that eating kiwi at a specific time of day is universally better, you can still adjust your intake based on your health goals. If you’re simply aiming to boost your vitamin C intake, one kiwi a day is all you need. But studies looking at kiwi consumption and sleep suggest that eating two before bed may offer added benefits.
In that case, it’s important to keep digestion in mind. High-fiber foods like kiwi can speed up gut motility to an uncomfortable degree, Lindsay said. “For people who do not suffer from constipation, it is advisable to gradually increase dietary fiber from high fiber foods such as kiwi fruit,” she noted.
Similarly, she added, “for people with poor blood sugar control, it may be best to start with one kiwi fruit and monitor blood sugar response.”
