Going to the grocery store can be a stressful experience when you want to lose weight and don’t know where to start.

The best way to approach the situation is by preparing in advance, according to Julia Callahan, registered dietitian and owner of Atlanta Dietitian Services.

“You can’t go to the grocery store without a plan. The key for weight loss is to make your menu for the week,” she said.

Here are some of the foods she recommends when you’re writing your grocery list:

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Dairy

According to Callahan, dairy is a good source of calcium your body needs. Examples of healthy sources of dairy are Greek yogurt, low-fat milk, skim milk and park-skim mozzarella sticks. Greek yogurt can be a great substitute for mayonnaise or sour cream.

If you cannot have dairy because of an intolerance, food allergy or gastrointestinal disorder, try getting calcium from non-dairy milk sources, such as soy milk, almond milk  or cashew milk.

Fruits

Fruits are important sources of vitamins, anti-oxidants and fiber. Try snacking on fresh fruits or blending them into smoothies.

Callahan said blending does not affect the nutrients in fruits, but cooking or juicing fruits can make them lose some of their properties.

Foods that help you stay full

Choose foods that are high in fiber to help you stay full between meals. Plant-based foods and whole grains can help with that feeling of fullness, such as beans, lentils and other types of legumes.

Healthy fats

Yes, there is such a thing as healthy fat. Using olive oil, substituting avocados for your usual spreads, or snacking on nuts and seeds can help your body get these necessary fats.

Lean protein

When it comes to choosing proteins, legumes, fish, chicken and turkey are best. Remember to make sure the protein you choose is broiled, baked, roasted or grilled, so stay away from fried meats.

Callahan said at least 8 ounces of fish are recommended per week, and consumption of red meat should be limited (4 ounces per week at most).

Vegetables

Both starchy and non-starchy vegetables can greatly contribute to your diet.

Starchy vegetables are the healthy type of carbohydrates your body needs. Examples of these include several types of roots, bulbs and kernels, such as corn, potatoes, peas, pumpkin, parsnips, squash, zucchini and yams, according to the San Francisco Chronicle.

Non-starchy vegetables are low in calories, high in fiber and great at helping you stay full. Some examples of these are broccoli, lettuce, spinach, onions, asparagus, cauliflower, cucumber, peppers, mushrooms and tomatoes.

Callahan said it’s crucial to ensure half of your plate is made up of vegetables.

Other suggestions

"Bottom line, read food labels."

Callahan emphasized the importance of knowing your food’s nutritional content when it comes to shedding pounds.

She also said it's imperative to avoid packaged foods, processed foods and foods with extra sodium or added sugars.

Remember to focus on what works best for you and your family. Meal prepping can become overwhelming, so try to find quick, healthy recipes online to ease the burden.

Happy shopping.