I used to think food was just about energy and taste. Calories in, calories out. But over the years, I’ve realized what I eat plays a huge role in how I feel .

And not just in the “too much coffee makes me jittery” kind of way. I’m talking about mood, clarity, patience, and whether I end the day feeling drained or steady.

Here’s the tricky part: the foods that secretly sap your energy and happiness aren’t always the ones you expect. Some of them masquerade as “normal” choices, things you grab without thinking.

But when I started paying closer attention, I noticed patterns—and making small swaps changed everything.

Let’s dig into the eight biggest culprits and the vegan fixes that actually work.

1. Skipping protein at breakfast

Have you ever started your day with toast and jam, only to crash by 10 a.m.? Been there.

Protein helps keep blood sugar stable, which directly affects mood. Without it, your energy spikes and plummets—and so does your patience. Experts like Dr. Uma Naidoo, author of This Is Your Brain on Food , emphasize the link between nutrition and emotional health.

The fix? Add plant-based protein early in the day. A tofu scramble, chia seed pudding, or even a smoothie with pea protein can make a world of difference. These options aren’t heavy, but they keep me grounded until lunch.

2. Relying on ultra-processed snacks

That mid-afternoon vending machine run? It feels like a lifesaver in the moment. But processed snacks loaded with additives and refined sugar leave you feeling sluggish afterward.

I used to grab a bag of chips between writing sessions, thinking it was harmless. But the crash that came later left me foggy—and not much fun to be around.

Now I prep roasted chickpeas, homemade trail mix, or even just apple slices with peanut butter. They satisfy the craving for crunch or sweetness but don’t drag my energy into the ground.

3. Drinking more caffeine than water

Coffee is my love language, but too much and I spiral. Irritability, anxiety, restless sleep—it’s all connected. And half the time, what I really need isn’t another latte. It’s hydration.

As noted by researchers , even mild dehydration can affect mood and focus. The irony? Caffeine is a diuretic, which makes the water deficit worse.

These days, I alternate: one coffee, then a big glass of water. I’ve also swapped my late-afternoon coffee for iced green tea or a ginger-lemon infusion.

My brain still gets a little lift, but my mood stays steady into the evening.

4. Forgetting leafy greens

Greens aren’t just “healthy filler.” They’re packed with folate and magnesium, both of which are tied to brain health and mood regulation.

There were weeks when my plate was heavy on carbs and protein but light on vegetables, and I could feel the difference—sluggish digestion, low energy, and a creeping irritability I couldn’t quite place.

The fix is simple: throw spinach into smoothies, sauté kale with garlic, or keep a bag of mixed greens ready for quick lunches. It’s not about salads every day; it’s about weaving greens into meals so they don’t feel like an afterthought.

5. Overdoing refined carbs

Comfort food is real, and I’ll never say no to a good bowl of pasta. But I’ve noticed that when white bread, pastries, and pizza slices become the default, my energy dips and mood swings spike.

Health experts say refined carbs aren’t really good for us, as they’re linked to increased risk of many diseases, including obesity, heart disease and type 2 diabetes.

Plus, energy-wise, they don’t carry you very far. Refined carbs burn fast, leaving you with that infamous crash.

The swap? Go for complex carbs with fiber and nutrients intact. Quinoa, brown rice, sweet potatoes, or whole-grain bread keep me satisfied without the rollercoaster effect. And honestly, roasted sweet potatoes with a sprinkle of cinnamon feel just as comforting as dessert.

6. Ignoring omega-3s

Here’s one I overlooked for years. Omega-3 fatty acids play a key role in brain function and emotional well-being. When I wasn’t paying attention, I realized I rarely ate foods that contained them.

According to experts , omega-3s are essential for building the brain’s structure and protecting against depression and mood disorders.

That hit me, since I don’t eat fish. So as a solution, I make a point of adding walnuts, flaxseed, chia seeds, and algae-based supplements to my routine.

A tablespoon of ground flax in my oatmeal doesn’t just boost nutrition—it keeps my mood steadier than I would have believed.

7. Using sugar as a reward

Ever thought, “I deserve this cookie after a long day”? Me too.

The problem is, sugar’s quick hit of dopamine fades fast—and what follows can be a low that feels worse than where you started.

I realized I was using sugar as a mood regulator, and it wasn’t working. The fix wasn’t cutting sugar completely—it was finding swaps that still felt indulgent but didn’t wreck my mood.

Dates stuffed with almond butter, dark chocolate with almonds, or homemade banana “nice cream” scratch the itch. They still feel like treats but don’t leave me cranky an hour later.

8. Forgetting to make food social

This last one isn’t about nutrients. It’s about context. Eating alone at my desk, mindlessly scrolling, always leaves me feeling emptier than when I started.

Food is connection. It’s one of the simplest ways to nourish not just the body but the spirit. And when meals lose that social element, moods take a hit.

When I started making more effort to eat with my husband, invite a friend for lunch, or even just set my phone aside and be present , meals shifted from fuel to grounding rituals.

That shift—consuming with intention rather than distraction—turned food into a mood booster, no matter what was on the plate.

Final thoughts

None of these mistakes are catastrophic on their own. But together? They chip away at your mood and energy in ways you might not even notice until you feel off-balance.

The beauty is that the swaps are simple. More plants, more water, more intention. Less defaulting to sugar, caffeine, or processed foods.

Food won’t solve every emotional dip, but it can absolutely support steadier energy and a brighter outlook. And honestly, those small adjustments add up.

So next time you’re dragging through the afternoon or snapping for no reason, ask yourself: is it really my mood… or is it my menu?