Do you run out for coffee, tea or chocolate at 3 p.m.? I used to and the line in the coffee shop was always long. It's traditionally siesta time in some countries and I can understand the need for a nap or a pick-me-up. Sometimes it seems a long time until the day ends and we need something to energize us to make it through.
Caffeine causes spikes and drops in blood sugar which causes the lift and the subsequent crash. This leads to mood swings and irritability. There are gentler ways to get your caffeine than coffee. Green tea comes to mind, it has much less caffeine - 25 mg on average as opposed to coffee's 125 mg per 8oz cup. And that's regular coffee, not a bold Starbuck's which can have 180 mg of caffeine in a short. Black tea has about 60 mg which is at least half that of coffee. Skip the sugar and use a natural sweetener such as honey or stevia.
I think a better option is to take a ten minute walk. The walk will clear the cobwebs from your brain and the exercise will get the blood flowing. You'll feel refreshed and energized without experiencing a crash later on. And you'll have gotten in 10 minutes of exercise. If you do that twice more during the day you've hit the recommended 30 minutes.
Another option is to have a green juice or smoothie. If you are new to green drinks I'd recommend starting with ones that are more fruit and have some greens added in. The fruit will make it sweet and delicious and the leafy greens are full of nutrients and are powerhouses for our bodies. They purify the blood, strengthen the immune system and improve circulation. I also find they help curb my cravings, after drinking one I'm not looking for snacks or sweets.
A final thought: You could just be slightly dehydrated. Try drinking a glass of water and waiting 10 minutes to see how you feel.
I'd love to help you on your healthy journey. Please email me at firstname.lastname@example.org or visit my website, http://empoweredplate.com/. Together we can create plan to help you reach your goals of eating better, having more energy, less stress and feeling vital.