Twenty minutes of simmering and you've got a low calorie Wednesday dinner that's warming without being heavy. Shrimp cooks fast, vegetables add bulk without calories.
Heat 1 tbsp olive oil in a large soup pot over medium heat. Add the diced onion and sauté until translucent, about 2-3 minutes.
Stir in garlic, followed by celery and carrot. Cook for 2 minutes, stirring occasionally, to sweat the vegetables without browning.
Add the zucchini and fresh thyme; sauté another minute, then pour in 4 cups low sodium chicken broth. Raise heat to high and bring to a boil.
Lower heat to medium and simmer uncovered for 10 minutes, until vegetables are just tender but still hold their shape.
Add shrimp and spinach. Gently simmer for 3-4 minutes, stirring once, just until shrimp turns pink and opaque, and spinach has wilted. Avoid overcooking.
Season with black pepper, salt, and finish with lemon juice. Taste and adjust seasoning as needed before serving hot.