White Bread
White bread might look harmless, but it’s packed with refined flour that your body breaks down quickly, causing a rapid spike in blood sugar. This sugar rush is followed by a crash, leaving you feeling sluggish and tired. In 2024, a study published in Nutrients confirmed that high-glycemic foods like white bread can impair energy and focus within two hours of consumption. Many people don’t realize that swapping white bread for whole grain alternatives can keep energy levels steadier throughout the day. The lack of fiber in white bread means your body processes it too fast, missing the slow-release energy you get from whole grains. If you’re reaching for toast in the morning, consider how it might be setting you up for a mid-morning slump.
Sugary Breakfast Cereals
Sugary breakfast cereals are a morning staple for many, but their high sugar content can sabotage your energy. The American Heart Association warned in 2023 that these cereals can contain up to 20 grams of sugar per serving, which is nearly the daily recommended limit for kids. This sugar overload leads to a spike and crash in blood glucose, making you feel drained before noon. Recent surveys have shown that adults and children who eat these cereals regularly report feeling tired earlier in the day compared to those who eat protein-rich breakfasts. The quick energy might feel good for a moment, but it’s a short-lived boost. Swapping to oats or eggs can help maintain balanced energy all morning.
Energy Drinks
Energy drinks promise a quick fix, but the jolt they give is often followed by a bigger crash. In 2024, The Journal of the American Medical Association reported that energy drink consumers had higher rates of fatigue later in the day compared to coffee drinkers. The combination of high caffeine and sugar causes a rapid increase in alertness, but as your body processes these ingredients, energy levels plummet. Many people report feeling irritable and exhausted once the effects wear off. It’s a bit like running your engine too hard; eventually, you run out of gas. Choosing water or unsweetened herbal tea can help you avoid this rollercoaster.
Processed Meats
Processed meats like sausages, bacon, and deli slices are convenient, but research from the World Health Organization in 2023 linked them to increased feelings of tiredness and sluggishness. These foods are often loaded with salt and preservatives, which can dehydrate you and disrupt your body’s natural rhythms. Sodium-rich foods make you thirsty and can increase your blood pressure, both factors that leave you feeling wiped out. While a bacon sandwich might sound tempting, it’s likely to leave you feeling lethargic by lunchtime. Lean, fresh proteins are a better option for lasting energy.
Fried Foods
Fried foods, such as french fries and fried chicken, are popular comfort foods, but their heavy fat content can weigh you down. According to a 2024 study in Appetite, people who consumed fried foods at lunch reported 30% more fatigue in the afternoon compared to those who ate baked or grilled options. These foods are hard to digest, requiring your body to use more energy for digestion and leaving less available for you. The sluggish feeling after a fast-food meal isn’t just in your head—it’s backed by science. Opting for baked or grilled foods can help you avoid the afternoon slump.
Pastries and Doughnuts
Pastries, doughnuts, and other baked sweets are loaded with sugar and refined flour, which are notorious for causing energy crashes. In 2023, the National Institutes of Health highlighted that people who regularly eat these treats experience more frequent mood swings and higher levels of fatigue. The quick release of sugar gives a brief high, but it doesn’t last. Soon after, blood sugar drops, leaving you tired and craving more sweets. If you’re reaching for a pastry with your coffee, it might give you a momentary lift, but don’t be surprised if you’re yawning soon after.
Diet Soda
Diet sodas are often marketed as a healthier alternative, but research in 2024 from the University of Sydney found that artificial sweeteners can disrupt gut bacteria, leading to fatigue and poor focus. The lack of real sugar means your body doesn’t get any actual energy, and the chemicals may even trick your brain into thinking you’re hungry or tired. Many people report feeling more sluggish after drinking diet sodas compared to water or coffee. The artificial ingredients can also cause bloating, making you feel uncomfortable and tired. Switching to sparkling water with a slice of lemon is a refreshing alternative.
Cheese
Cheese is delicious and comforting, but for some, it can be a hidden source of tiredness. A 2023 study in the journal Nutritional Neuroscience found that the high saturated fat in cheese can slow digestion and make you feel more lethargic. People who ate cheese-heavy meals reported feeling sleepy and less motivated within an hour. The body has to work hard to process all that fat, using up energy you’d rather keep for yourself. If you love cheese, try using it in moderation and balancing your meals with plenty of fresh fruits and vegetables.
Bananas
Although bananas are often thought of as an energy food, new research from the University of Cambridge in 2025 suggests that their high magnesium content can actually relax muscles and make you feel sleepy, especially if eaten in large amounts. Athletes sometimes use bananas to wind down after training for exactly this reason. While they’re a great snack for steady energy, eating too many at once might have the opposite effect. For most people, one banana is perfect for a quick pick-me-up, but several might leave you ready for a nap. Moderation is key to avoiding that unexpected tiredness.
Yogurt
Yogurt is often praised as a healthy snack, but not all yogurts are the same when it comes to energy. In 2024, Consumer Reports found that many flavored yogurts contain as much sugar as a candy bar, leading to the same spike-and-crash effect as other sugary foods. People who ate these yogurts for breakfast were more likely to feel tired by mid-morning compared to those who ate unsweetened Greek yogurt. The added sugar quickly raises your energy, but it falls just as fast, leaving you drained. Choosing plain yogurt and adding your own fruit can help keep your energy steady.
