As summer fades and the rhythm of fall begins to take hold, many adults find themselves feeling drained, scattered, or sluggish, especially in those early September weeks when routines are shifting significantly. You may chalk it up to the changing seasons, but we often see another common culprit that sneaks in during the laid-back days of summer: too much added sugar.
The summer months tend to bring a more relaxed approach to food and routine. Think iced coffees with syrup, extra snacks during road trips, backyard s'mores, and refreshing cocktails on patios. There’s nothing wrong with enjoying those moments, they're part of the joy of summer. But once fall arrives and we shift back into a more structured schedule, those lingering high-sugar habits can leave us feeling foggy, tired, and unmotivated.
We call this the “back-to-school sugar slump,” and it doesn’t just affect kids.
Let’s explore why adults experience this seasonal crash, how sugar impacts your focus and energy, and what small, supportive steps you can take to feel your best as you head into fall.
What the Sugar Slump Looks Like in Adults
The signs are often subtle but become harder to ignore when daily routines ramp up. You might notice:
- Mid-morning or afternoon energy crashes, often after a sugary breakfast or snack
- Mood swings or irritability, especially when hungry
- Increased cravings for sweets or refined carbs
- Poor concentration during work or other responsibilities
- Trouble sleeping or feeling unrefreshed, even after a full night’s rest
You may even find yourself reaching for coffee more often or hitting the vending machine at 3 p.m. just trying to push through fatigue that’s actually tied to what you’re eating, not just how much you're sleeping.
Why It Happens: Sugar’s Rollercoaster Effect
Sugar is a fast-acting carbohydrate that digests quickly and spikes your blood glucose. When you eat or drink something with a lot of added sugar, especially without protein or fiber, it can give you a quick burst of energy followed by a steep crash. This drop in blood sugar can leave you feeling tired, irritable, and craving more sugar to “fix” it.
This cycle can repeat itself throughout the day, making it hard to concentrate, stay full between meals, or regulate your mood. It also impacts hormones like insulin and cortisol, which play key roles in how your body manages stress and stores energy.
When we return to more structured workdays, commutes, and routines in the fall, this blood sugar rollercoaster becomes much more noticeable. What may have worked during slower summer mornings now leaves you lagging behind.
Want a deeper dive into how blood sugar works and tips for stabilizing it? Check out our article on managing blood sugar levels. →
How to Reset, Without Restriction or Shame
First, let’s be clear: this is not about cutting sugar completely or labeling foods as “good” or “bad.” Sugar is not the enemy. It’s part of many foods we love and share with others. But when it becomes a dominant source of energy instead of a balanced part of your diet, it can impact the emotional regulation, energy, and resilience you need to thrive day to day.
Here are supportive, realistic ways to beat the sugar slump as you shift into fall.
1. Start the Day with Sustained Energy
Breakfast is your foundation for the day. Skip the sugar-laden cereal, muffin, or flavored coffee and choose a meal that includes protein, healthy fats, and fiber. This combo supports stable blood sugar and keeps you full for longer.
Try:
- Scrambled eggs with avocado toast and a side of fruit
- Greek yogurt with chia seeds, walnuts, and berries
- A protein smoothie with spinach, nut butter, and a banana
- Oatmeal topped with almond butter and pumpkin seeds
2. Rethink Midday Snacks
It’s easy to reach for quick snacks like granola bars, pastries, or sugary beverages when your energy dips. Instead, choose snacks that combine protein and fiber to satisfy you and support your energy.
Snack ideas:
- Apple slices with peanut butter
- Hummus with raw veggies
- Hard-boiled eggs and whole grain crackers
- Cottage cheese with sliced peaches
- A handful of nuts and a square of dark chocolate
3. Check Your Drinks
Added sugar can sneak into your routine through beverages without you realizing it. Sweetened lattes, soda, teas, energy drinks, and even store-bought smoothies can add up quickly.
Hydration is important for energy and focus. Try:
- Water with lemon, cucumber, or fresh mint
- Unsweetened iced tea or sparkling water
- A homemade smoothie with minimal added sugar
- Switching one sugary drink per day for water or herbal tea
Staying hydrated is a powerful way to support energy, focus, and overall health. Explore our complete hydration guide for tips, infused water recipes, and more here. →
4. Balance Blood Sugar at Every Meal
Every meal doesn’t need to be perfect. But when you focus on balance, building plates that include protein, fiber-rich carbs, and healthy fats, your energy stays more consistent.
Aim for a “balanced plate” like this:
- Half vegetables or fruit
- A quarter whole grains or starchy vegetables
- A quarter protein (beans, chicken, tofu, eggs, fish, etc.)
- A source of healthy fats like a drizzle of olive oil, avocado, or nuts for fat
This approach helps you feel full, supports brain function, and reduces the likelihood of sugar cravings later on.
5. Give Yourself Grace and Intention
Breaking out of the sugar slump isn’t about rigid rules, it’s about tuning in. Notice how certain foods make you feel. Do you crash after that pastry at 10 a.m.? Do you sleep better when your dinner includes veggies and protein?
Try not to moralize food as “good” or “bad.” Instead, think in terms of how meals and snacks serve your energy, focus, and mood. That way, when you do choose a sweet treat, you’re doing so with enjoyment, not because you’re running on empty.
Final Thoughts from Your Dietitian
The back-to-school season isn’t just for kids. For many adults, it’s a time to reset priorities, build healthier habits, and reclaim routines that support their best selves.
If you’ve been feeling foggy, tired, or a little “off” since summer ended, it might be time to look gently at your sugar intake, not with judgment, but with curiosity. Sometimes, just a few intentional changes can reignite your focus and energy in a powerful way.
Give yourself permission to start small. One more balanced breakfast. One less sugary drink. One afternoon snack that satisfies instead of spikes. Over time, these changes create the foundation for a more energized, clear-headed, and vibrant fall!
This article was written by Katie Gould, MA, RDN, LD, CDCES, a dietitian at Mend.
