The Relationship Between Nutrition and Disease

 In modern society, most people live with busy schedules, which makes it easy to overlook the importance of nutrition to the human body. Both nutrient deficiencies and excessive intake can place a burden on the body and may even lead to the development of diseases. Here, we will explore the relationship between nutrition and disease to help everyone understand the importance of a balanced diet for health, while also offering methods and approaches to improve poor eating habits.

What is malnutrition?
Malnutrition refers to deficiencies, excesses, or imbalances of nutrients caused by an unbalanced diet.
Generally, the term “malnutrition” is used to describe nutrient deficiencies, such as insufficient intake of calories, protein, and micronutrients. However, nutrient excess also counts as a form of malnutrition!

Nutrition and Disease

• Mental disorders (depression, bipolar disorder, addiction, etc.)
  A lack of certain nutrients may cause brain dysfunction, while overeating can increase the risk of depression or sleep disorders.

• Gastrointestinal (gut microbiome) problems (such as diarrhea, colon cancer, liver and gallbladder diseases, metabolic disorders, cardiovascular diseases, skin diseases, and mental health issues)
  Diet is one of the most important factors affecting gut health and gut bacteria. The “father of probiotics,” Élie Metchnikoff, once said, “Death begins in the colon.” Clearly, maintaining gut health through a proper diet is crucial.

• Blood sugar–related diseases (diabetes, mental disorders, heart disease, etc.)
  Maintaining regular eating habits is vital. Fluctuating blood sugar levels can cause mood disorders, and even depression and anxiety. But this doesn’t mean you should snack constantly—frequent snacking disrupts appetite regulation and insulin function.

• Sleep problems (insomnia, shallow sleep, poor rest)
  Overconsumption of caffeine—such as coffee, strong tea, or soda—can interfere with sleep. Instead, it is helpful to consume tryptophan, theanine, calcium, magnesium, and B vitamins.

• Chronic diseases (diabetes, hypertension, obesity, hyperlipidemia, gout, etc.)

• Other adverse effects (loss of appetite, fatigue, poor physical performance, unexplained aches, difficulty concentrating, lack of motivation, apathy, irritability, sleepiness, etc.)

Nutrition-related diseases among Taiwanese people
(Reference: Nutrition and Health Survey in Taiwan [2017–2020], Section 5: Nutrition-Related Health and Chronic Diseases)

• Rising metabolic risks linked to obesity
  Among adults aged 19 and older, the prevalence of metabolic syndrome has increased over time for both men and women, with men consistently showing higher rates. The increase in prevalence was similar across both genders in recent surveys.

• Rising prevalence of hyperlipidemia among adults aged 19 and older
  Blood lipid abnormalities significantly increase after age 45 for both men and women, and among women aged 65 and above, the prevalence is higher than in men. Compared to the 2013–2016 survey, the most recent data shows an upward trend in hyperlipidemia.

• Vitamin deficiencies—most severe in vitamin D
  Vitamin D deficiency is most common among individuals aged 13–44, followed by vitamin B6 deficiency, which affects about 10% of both men and women.

• Anemia in women aged 13–64, possibly related to iron deficiency
  Anemia in this group is likely linked to iron deficiency and may also be associated with the menstrual cycle.

• Poor nutritional status among women of childbearing age
  Many show deficiencies in vitamin D, folate, iodine, and iron.

• Iodine imbalance across age groups
  Younger individuals (children, teens, and adults aged 19–44) tend to have excess iodine intake due to eating out frequently, where iodized salt is used. In contrast, over half of those aged 45 and above have iodine deficiency. Therefore, it is recommended that older adults continue to use iodized salt at home.

World Health Organization (WHO) perspective
WHO emphasizes five key principles for a healthy diet:

1. Eat a variety of foods
   Include vegetables at every meal, focusing on seasonal and diverse options.

2. Limit sugar intake to less than 10% of total daily calories
   Sugar is found not only in snacks and drinks but also in sauces, braised dishes, processed meats, and condiments like ketchup and mayonnaise. WHO suggests replacing sugary foods with fresh fruits and vegetables.

3. Replace saturated and trans fats with unsaturated fats
   Ways to reduce intake of harmful fats include:

   • Steaming or boiling instead of frying.

   • Using polyunsaturated oils (soybean, canola, sunflower) instead of butter, lard, or ghee.

   • Choosing low-fat dairy and lean meats, trimming visible fat, and preferring white meat over red meat.

   • Reading nutrition labels and limiting baked goods, fried foods, and packaged snacks containing trans fats.

4. Limit salt intake to less than 5 grams per day (about one teaspoon), and use iodized salt
   To reduce salt:

   • Use less salt and high-sodium condiments like soy sauce.

   • Avoid salty snacks like potato chips.

   • Choose products with lower sodium based on nutrition labels.

   • Remove condiments from the table to break the habit of adding extra salt. Taste buds will adjust over time.

   • Increase potassium intake through fresh fruits and vegetables, as it helps counteract sodium’s negative impact on blood pressure.

5. Limit alcohol consumption
   Excessive or frequent drinking increases the risk of liver damage, cancer, heart disease, and mental health issues. WHO states that there is no “safe” level of alcohol intake, as even small amounts can negatively affect health.

Improving Eating Habits (Methods and Approaches)
Balanced eating means consuming all six food groups daily: whole grains, dairy, protein-rich foods (beans, fish, eggs, meat), vegetables, fruits, and oils/nuts/seeds.

Caloric intake should be adjusted according to one’s body type, age, and activity level, without exceeding or falling below one’s basal metabolic rate (BMR).

Practical approaches include:

• Following Taiwan’s “My Plate” dietary guidelines.

• Trying the DASH diet or the Mediterranean diet.

• Consulting with doctors, nutritionists, or fitness coaches.

• Eating slowly, avoiding distractions, rejecting oversized packages, drinking more water, and ensuring adequate sleep.

• Avoiding late-night eating.

• Setting meaningful health goals.

• Finding a partner to maintain healthy habits together.

Diet is one of the most important aspects of human life and is directly linked to health. Poor dietary habits often accumulate over time, placing a burden on the body that is difficult to notice immediately. Once problems occur, they can be hard to reverse. Many people focus more on dieting for weight loss rather than eating healthily, sometimes adopting extreme approaches that ignore the importance of proper nutrition. In reality, successful weight management depends on correct dietary control. By paying closer attention to our daily eating habits, we can achieve a healthier and more fulfilling life.