If you are what you eat, then does your diet also determine your mood? More importantly, can you manipulate your diet to ward off depression or even rescue yourself from a big slump? The answer to both questions: Yes!

Research shows that something as simple as a can of soda or a glass of orange juice can raise blood sugar levels – something many of us know – but that one thing can also cause depression and irritability.

Simply put, high glycemic foods – those with lots of sugar, white rice, pasta and bread – cause spikes in the blood sugar levels, while low glycemic level foods leave you feeling full longer and they don’t cause these blood sugar spikes.

Some little exchanges – drinking sparkling water instead of a soda, eating quinoa instead of white potatoes, or fresh fruit instead of a sugary dessert – can make you feel better in all sorts of ways. You are satiated and don’t keep coming back for more food, and not only do you feel better physically, but you avoid the tendency toward depression.

So, how does this translate into how you feel after you eat your favorite meal? 

According to Julie Connors, a registered dietitian and functional medical practitioner, there is a tremendous, complex link between food and the brain. Eating right, she says, can help people to reduce depression and anxiety. There is a direct correlation between what you eat and how happy you may be.

For instance, dehydration, a common condition, is linked to mental acuity, fatigue and energy. The custom of drinking too much coffee, or other caffeinated drinks, contributes to dehydration and affects people who probably don’t even realize what is going on.

People come to Connors’ practice, Healthy Weighs in Brookfield, Conn., feeling out of sorts, tired of anti-depressants, perhaps seeing six different doctors for assorted problems, and she researches their backgrounds including their level of stress, diet, exercise, and relationships.

“The gut is the foundation of the body and directly affects mental health,” she says. People often don’t realize how specific foods contribute to not only how they feel physically, but mentally.

For instance, a vitamin D deficiency, something which is fairly common, has a direct link to joint pain and depression. Not getting enough antioxidants or fiber also contributes to mental health, Connors says. People with food sensitivities, like allergies and gluten intolerance are often affected by accompanying depression.

You can change your diet and feel better. And if there are certain things you just can’t stomach, say Brussels sprouts or other cruciferous vegetables, there are supplements available to correct deficiencies. In other words, there is no need to let your diet rule your emotions. Key changes can make you feel happier.

Although you may understand which foods are good for you – and which aren’t – keeping a food diary may be evidence that you aren’t eating quite as well as you thought.

Connors notes that many people, when they begin to keep a food diary, are astounded as how badly they eat. “You may say you like healthy foods, but are you really eating them?” she asked.

If you want to start feeling better now, what can you do?

• No. 1: Eat a nutrient-rich diet. That means get all the colors of the rainbow in your food daily by eating lots of fresh fruits and vegetables.
• No 2: Make sure you get lots of hydration. Reduce caffeinated drinks and sodas. These drinks dehydrate you – water is always better – and often are a source of unwanted sugar.
• No 3: Keep a food diary. That means be really honest. Don’t write down what you know you should eat, but what you really eat and when.
• No 4: Get moving. Get some physical activity. If you are just sitting all day it impacts you both physically and mentally.
• No 5: Visit a registered dietitian. Such consultations, to design a diet that’s right for you, are usually covered by insurance, something many people don’t realize.