If eyes are the 'windows to the soul', hair gives many clues about our state of health, especially when hair loss is excessive. In some cases, it may be related to changes in diet, as trichologist Anabel Kingsley, who studies and treats hair, explains to the Daily Express.

"The most common cause of excessive daily hair loss in my clients is the lack of a healthy, balanced and varied diet," she says. According to the expert, one of the biggest mistakes is 'skipping' the first meal of the day. "I always ask for a summary of a typical day and, often, breakfast consists of just a coffee. However, after ten or more hours of fasting, all cells need to be nourished."

Read Also: Two superfoods that are 'weapons' against dementia and cancer (Portuguese version)

As if that were not enough, "I often see problems with hair growth and quality when someone does not research plant-based diets before starting one. Vegans should take a vitamin B12 supplement, which is only found naturally in animal products, since its deficiency causes excessive hair loss". In addition, "iron and zinc are less bioavailable in plant-based foods and deficiencies of both cause hair loss, so it is advisable to take supplements and have annual blood tests to monitor levels", she also says. 

She also adds that vitamin D "has a significant impact on the hair growth cycle and scalp health". And that's not all. A lack of iron in the body can also lead to hair loss and weaken the strands. 

Read Also: Clarins' viral 'lip oil' has three new colours (Portuguese version)

Hair loss is also common in people who are losing weight, as well as a decrease in the volume and density of the strands. "Rapid weight loss and drastic restriction of calorie and nutrient intake almost always cause hair loss," says the trichologist.

Hair also weakens with a lack of protein. "Hair is made up mostly of a protein called keratin. A lack of protein in the diet can cause the strands to become weak and brittle. So, try to include a palm-sized portion of a protein, such as cottage cheese, lean meats, quinoa, eggs, beans and oily fish in all your meals." If you have difficulty doing so, a daily protein supplement may help, although "they are not magic".

The same happens when you drastically cut your consumption of carbohydrates and healthy fats. 

Read Also: Daily care to control the symptoms of atopic dermatitis (Portuguese version)