Can i lose weight on 1800 calorie diet . i 6 foot 1 eat sandwich whole grain bread turkey breast one slice cheese green apple green tea greek yogurt?

You can as long as: calories burned exceed calories consumed. Drink at least 8 - 8 oz glasses of water per day. Try for 8 hours of sleep/night. Aim for at least 5 servings of vegetables & 4 servings of fruit per day. Use whole grain when possible. Avoid sodas, alcohol & junk carbohydrates. Get in a good mix of aerobic & weight lifting exercises.