More commonly touted for improving immunity and preventing disease, vitamin C isn't often associated with weight loss. But because it's an antioxidant, vitamin C is even more important when people who are overweight or obese are trying to lose weight. This is because even small increases in weight can trigger inflammation, which in turn increases production of free radicals. This leads to a cascade of hormonal and metabolic effects (such as insulin resistance) that may encourage more weight gain.

Meeting antioxidant needs is crucial for stopping inflammatory-related weight gain, and research suggests that overweight individuals have higher needs due to greater free radical production. Vitamin C is one of the most important nutrients to consume, yet data suggests most of us don't meet our daily recommendations.

Best Sources of Vitamin C (Daily Value for vitamin C is 90 mg):

1. Red bell pepper: a ½-cup serving has 95 mg

2. Orange: one medium orange has 70 mg

3. Kiwi: one medium has 64 mg

4. Cooked broccoli: a ½-cup serving has 51 mg

5. Sliced strawberries: a ½-cup serving has 49 mg

6. Cooked Brussels sprouts: a ½-cup serving has 48 mg

7. Grapefruit: one half of a grapefruit has 39 mg

Carotenoids are a family of biologically active compounds that include beta carotene, lycopene and lutein, and they give certain fruits and vegetables their red, orange and yellow coloring. One study compared phytochemical intake to body weight and found that higher intakes of carotenoid-rich foods were associated with lower body weights in participants. Additionally, as BMI increased, carotenoid intake decreased. Yet no significant differences in calorie intake were noted between the groups.

This could be due to several things, the most obvious of which is that people at healthy weights likely ate more fruits and vegetables. But researchers think the antioxidant activity of carotenoids also plays a role by reducing inflammation. This is because systemic inflammation is associated with hormonal imbalances and insulin resistance, two effects that promote weight gain, not weight loss. So it seems loading up on carotenoid-rich food may promote weight loss, along with stopping free radicals that could trigger cancer and other diseases.

Best Sources of Carotenoids (There is no DV for carotenoids, but these carotenoids are a form of vitamin A found in plants. The Daily Value for Vitamin A is 900 mcg RAE).

1. Baked sweet potato: 1 medium has 1,403 mcg

2. Mashed pumpkin: 1 cup has 705 mcg

3. Raw carrots: ½ cup has 459 mcg

4. Cantaloupe: ½ cup has 135 mcg

5. Red bell pepper: ½ cup has 117 mcg

6. Mango: 1 medium has 112 mcg

Adequate iron stores enable hemoglobin in red blood cells to carry oxygen to cells throughout the body. But when iron stores and levels are low, red blood cells aren't able to deliver oxygen which impairs cells' ability to metabolize energy. Iron-deficiency anemia develops when this continues, and common side effects are pale skin, fatigue and sensitivity to cold temperatures. This lack of oxygen may also impede weight loss in some individuals. In fact, a 2014 study suggested that treating this type of anemia with iron supplementation resulted in improvements in hemoglobin levels, but also decreases in body weight, waist measurements and BMI.

Anemia isn't always due to a lack of iron, and there can be side effects from taking iron if not needed. Because of this, focus on foods first. Then, if needed, see your doctor to determine next steps. (P.S. When possible, try to pair your iron-rich recipes with foods high in vitamin C to increase absorption!)

Best Sources of Iron (Daily Value for iron is 18 mg):

1. Fortified breakfast cereals: 1 serving has 18 mg

2. Legumes such as white beans, kidney beans and chickpeas: 1 cup has 4-8 mg

3. Dark chocolate: a 1½-oz. serving has 3.5 mg

4. Tofu: ½ cup has 3 mg

5. Cooked lentils: ½ cup has 3 mg

6. Braised beef round: 3 oz. has 2 mg