Core Viewpoint - The latest research indicates that consuming high-quality carbohydrates, such as whole grains, legumes, vegetables, and fruits, can promote healthier aging and may even make individuals appear younger than their actual age [6][8][9]. Group 1: Health Benefits of High-Quality Carbohydrates - A study published in the Journal of the American Medical Association in May 2025 highlights that high-quality carbohydrates can be beneficial for healthy aging [6]. - The analysis of 32 years of tracking data shows that increased consumption of high-quality carbohydrates correlates with a higher likelihood of healthy aging [8]. - High-quality carbohydrates can reduce the risk of health issues and slow down aging, with individuals consuming these foods appearing an average of 1.2 years younger than their peers [8][9]. Group 2: Characteristics of High-Quality Carbohydrates - High-quality carbohydrates are characterized by high dietary fiber content, low glycemic index (GI), and rich nutritional value, which includes vitamins, minerals, and antioxidants [10]. - These carbohydrates help in delaying digestion, enhancing satiety, and reducing calorie intake, while also minimizing blood sugar fluctuations and lowering diabetes risk [10]. Group 3: Sources of High-Quality Carbohydrates - The five main sources of high-quality carbohydrates include whole grains, legumes, starchy vegetables, and fruits [11]. - Whole grains are rich in dietary fiber, B vitamins, vitamin E, and unsaturated fatty acids, making them a healthier choice compared to refined grains [12]. - Legumes, such as red beans and green peas, provide a good source of protein and essential minerals [17]. - Starchy vegetables like pumpkin and lotus root are beneficial due to their high content of polysaccharides and antioxidants [18]. - Low-sugar fruits, such as apples and grapefruits, are recommended as healthy carbohydrate sources [19]. Group 4: Dietary Recommendations for High-Quality Carbohydrates - It is suggested that adults consume 200-300 grams of grain foods daily, with 50-150 grams coming from whole grains and legumes [22]. - Incorporating half a kilogram of fruits daily is recommended, focusing on those with lower sugar content [24]. - Combining legumes with grains can enhance dietary balance and protein intake [28]. - Emphasizing dark-colored vegetables can increase nutrient intake [30].

Nutritional Benefits of Watermelon - Watermelon has a high water content of over 90%, making it an excellent choice for hydration during hot summer days [3][5] - It contains vitamins and minerals such as vitamin C (5.7 mg/100g), dietary fiber, potassium, and magnesium, although these are not in high amounts compared to other fruits [3] - Lycopene, a natural pigment found in watermelon, has strong antioxidant properties and is linked to various health benefits, including cardiovascular disease prevention and cancer risk reduction [3][5] Comparison with Tomatoes - Watermelon contains a higher lycopene content than tomatoes, with levels ranging from 3.3 to 10 mg/100g in red-fleshed varieties, compared to 2.57 mg/100g in raw tomatoes [5] - The absorption rate of lycopene from watermelon is 40% more effective than that from tomatoes [5] Caloric Content - Watermelon is low in calories, with an average of 31 kcal/100g, and some varieties contain as low as 26 kcal/100g, which is less than half the calories of an apple [6] Sweetness and Sugar Content - The total sugar content in watermelon is 6.2 g/100g, with fructose being the predominant sugar at 3.36 g/100g [7] - Refrigerating watermelon enhances its sweetness due to the cold sweet characteristic of fructose [7] Glycemic Index and Load - Watermelon has a high glycemic index (GI) of 72, but its glycemic load (GL) is low at 4.8 for 100g, making it suitable for moderate consumption by diabetics [9] - The GL for 200g of watermelon is only 9.5, indicating minimal impact on blood sugar levels [9] Selection Tips - Choosing the right variety is crucial for sweetness; recommended varieties include "Little Sweet King," "Nanhui 8424," and "Super Dream" [11] - Tapping the watermelon can help determine ripeness; a dull sound indicates a ripe fruit [11] - A green stem indicates freshness, while a dry stem suggests the watermelon may be old [12] Consumption Guidelines - It is advisable to buy whole watermelons to avoid contamination from cut pieces [14] - Maintaining hygiene with cutting boards and utensils is important to prevent bacterial contamination [16] - Proper storage of cut watermelon with plastic wrap in the refrigerator can extend its freshness [16] - Recommended daily consumption is between 200g to 350g to avoid excessive calorie intake [16]