It’s natural to want a full, healthy head of hair. Your mane is one of the first things people notice, after all. If you find your hair is thin, brittle, or falling out—or a mix of these—you might be alarmed after waking up to a pillowcase full of loose hairs or noticing thinner locks. In response, your first stop might be the hair care aisle at your local pharmacy in search of volumizing products. Alternatively, you might consider shaving it all off. However, dermatologists and a registered dietitian say you may also want to audit your grocery list instead.
“Diet can absolutely affect your hair, and there are several ways it can have a negative impact,” said Dr. Chris Mohr, Ph.D., RD, a fitness and nutrition advisor for Garage Gym Reviews.
On the (hair)flipside, Dr. Mohr agrees with dermatologist that diet can also help your hair. Here’s what to know about diet and hair, including the nutrients your locks crave.
Is my diet affecting my hair?
Diet plays a role in hair health. Your locks need macro- and micronutrients, as well as calories, to grow. Therefore, Dermatologists and a registered dietitian say it’s possible to eat (or not eat) your way to a perpetually poor hair day. Here’s how and why diet may destroy your hair.
1. You’re consuming too few calories
When we speak about diet and nutrition, people often focus on cutting calories heavily. There is, of course, such a thing as eating too many calories. However, the opposite is also true — and it doesn’t do the hair any good.
“Not eating enough overall can weaken your hair because the body will always prioritize vital organs over hair growth,” Dr. Mohr said.
Dr. Viktoryia Kazlouskaya, MD, Ph.D., a dermatologist, agrees, stressing it’s vital to ensure you’re eating enough calories for your age, activity level, and weight. Your primary care physician or a registered dietitian is your best resource for customizing your caloric needs.
2. You’re not hitting your macronutrient goals
Macronutrients — carbs, protein and healthy fats — help your body thrive and keep your mane looking its best. Dr. Mohr said that a low intake of protein and fat can particularly damage hair.
“Low protein intake can cause shedding because hair is made mostly of keratin, which depends on consistent protein,” Dr. Mohr said. “Very low-fat diets can dry out hair because healthy fats support hormone production and help the scalp stay moisturized.”
3. Your hair needs more micronutrients
Despite the “micro” in their name, micronutrients can have a big-time impact on your hair health.
“A balanced diet rich in essential nutrients such as protein, iron, vitamins A, C, D, E, and zinc is vital for healthy hair,” said Dr. Michele Green, MD, a board-certified cosmetic dermatologist. “These nutrients are important because deficiencies can weaken hair follicles, leading to hair thinning or loss.”
Dr. Green added it’s especially important to hone in on iron deficiencies.
“When the body lacks sufficient iron, it may not produce enough hemoglobin, which is necessary for transporting oxygen to hair follicles,” she said. “This can impair their health and growth, resulting in noticeable hair thinning.”
4. Your hair isn’t loving processed foods
Listen, we get it. Sugary foods taste delicious. Ditto for fries, pepperoni, and processed foods. However, your hair may not agree with your taste buds on this one.
“Processed foods and sugars may contribute to metabolic changes, early diabetes, elevated cholesterol, and obesity,” Dr. Kazlouskaya said. “These changes can negatively affect hair growth.”
Dr. Mohr echoed these sentiments. He added that foods loaded with added sugar can trigger insulin swings, which can disrupt hormone levels, such as spiking dihydrotestosterone, which can affect hair follicles and the growth cycle.
Does diet help your hair?

Diet does not simply destroy your hair. Foods rich in omega-3 fatty acids, vitamins, and antioxidants can also support stronger, fuller, and healthier hair growth. Dr. Kazlouskaya said you can find these vital macro- and micro-nutrients in:
- Fatty fish, like salmon (omega-3s and protein)
- Other seafood, like oysters (zinc, iron, and protein)
- Eggs (protein, biotin, and vitamin D)
- Nuts (protein, healthy fats, and trace elements)
- Colorful fruits and vegetables, such as citrus and salmon (vitamins A, C, iron, and more)
What nutrition am I lacking if my hair is falling out?

When your diet lacks critical nutrients like iron and protein, your hair can become thinner and more brittle. The precise nutrient deficiencies are personal, though.
Dr. Mohr said that deficiencies that can cause hair loss include:
- Protein (your hair needs amino acids to build stronger strands)
- Vitamin D (influences the hair cycle, so low levels can increase shedding and slow regrowth)
- Iron (helps with oxygen delivery to the follicles, so low levels cause hairs to enter a resting or shedding phase)
Dr. Kazlouskaya usually advises her patients to track their food intake to ensure they’re getting enough calories and nutrients. However, she said that nutrient deficiencies are a less common cause of hair loss in men than in women, so it’s vital to explore other reasons for the issue. Dr. Green agrees.
“While diet is important, it is not the only factor affecting hair health,” Dr. Green said. “Hair loss or thinning can result from various causes, including genetics, hormonal changes, and environmental stressors. If you are experiencing hair breakage or hair loss, it is best to consult a board-certified dermatologist to determine the underlying cause and whether it may be linked to your diet.”
Takeaway

Your taste buds and stomach aren’t the only body parts that crave food. Your hair requires vital nutrients to grow and remain strong. For instance, iron delivers oxygen to your hair follicles, helping prevent excessive shedding. Since the hair is made up of mostly protein, too little of this macronutrient can lead to weaker, thinner strands. Additionally, diets high in processed and sugary foods can mess with the hormones that support hair regrowth. Still, diet isn’t the only culprit for hair loss. Additionally, hair loss may be a flag for another underlying condition, so it’s essential to get checked out if you’re concerned.
