Introduction
Leafy greens are nutrient-packed, low-calorie, edible plant leaves eaten as a vegetable. They are widely consumed for weight management and for making long-term lifestyle changes to maintain a healthy body weight. They offer a wide range of health benefits. Poor weight management increases the chances of developing several health problems including, but not limited to, diabetes, stroke, and certain types of cancers. This article intends to give more information on the most important things you need to know about leafy greens for weight management.
Nutritional value of leafy greens
Leafy greens, also known as dark green leafy vegetables or greens (such as kale, spinach, lettuce, and Swiss chard) are low in fat and sodium but rich in beneficial nutrients. Below are some of the nutrients present in leafy greens.
- Vitamin A maintains eye and skin health and protects the body against infections
- Vitamin C is essential for maintaining skin and dental health. It is especially important for healing cuts and wounds. When consumed with iron-rich foods, it promotes iron absorption
- Vitamin K is essential for blood clotting
- Folate (also known as folic acid) is required for the formation of new blood cells. It is especially essential for women in the childbearing age bracket because a diet with adequate folic acid may reduce the risks of having a baby with congenital disabilities
- Iron is essential for oxygen transport by red blood cells throughout the body. A diet rich in leafy greens may, therefore, help improve the function of the red blood cells, thereby reducing the risk of developing iron-deficiency anaemia
- Calcium is required for building and maintaining healthy, strong teeth and bones. It is also essential for normal blood clotting and proper muscle functioning. This is especially important during pregnancy, as the growing baby requires a substantial amount of calcium. Therefore pregnant women are encouraged to increase their intake of leafy greens and other foods high in calcium to meet the baby's demands
- Potassium helps the body keep a healthy blood pressure
Greens often contain bioactive compounds such as omega-3 fatty acids, niacin sulforaphane, flavonoids, and carotenoids that significantly support healthy lifestyle and prevent and slow down excessive weight gain. They also provide anti-inflammatory and antioxidant benefits that may give the body many health benefits, such as reduced risk for diseases like anaemia, Type II diabetes, cardiovascular diseases, muscular degeneration, and other diseases like cancer. They may also boost gut, bone, skin, and heart health, improve immunity, and slow cognitive decline associated with ageing.1
They are an important part of a healthy diet, and they may improve brain health and lower the risk of heart disease, cancer, and high blood pressure. They are low in calories and high in nutrient content. When cooked, they have about 10-35 calories per serving.
Greens have a high fibre content that supports digestive and heart health and manages blood sugar. It is essential to include fibre-rich foods in your diet and leafy vegetables are a good source. Research by the American Society for Nutrition shows that only 7%of adults' daily consumption meets the minimum daily requirement of at least 28 grams.2 Eating foods rich in fibre prevents constipation, improves gut health, stabilises blood sugar levels, provides satiety, and lowers the risk of type II diabetes, heart disease, and cancer. They are also rich in chlorophyll, which is known to alkalise the blood, boost energy, and strengthen the immune system.3
Benefits of leafy greens for weight management
Adding greens to your diet results in less calorie consumption without increasing hunger. Their high water and fibre content fills you up and keeps you feeling satisfied for longer, which in turn can help you lose weight. One of the most important benefits of consuming leafy greens is that compared to other foods; they are very low in calories and dense in essential nutrients the body needs to be healthy.
Hence, they are highly recommended for a weight loss or management diet. They also contain a fat-soluble vitamin called vitamin K, which is known to stimulate weight loss. A high vitamin K intake may support body weight reduction and loss of fat in the abdominal region.4 Recent studies also suggest that this nutrient can help reduce inflammation and plaque formation in the arteries, fight diabetes and delay the onset of bone diseases like osteoporosis.
Role of leafy greens in meal planning
Leafy greens are a great addition to various meals and can be incorporated into weekly meal plans. They are perfect for adding texture and subtle taste to meals while boosting your daily vegetable intake. Some ways to include them in your diet include the following:
- Added raw with dressing of choice in salads or mix with other proteins, fruits and whole grains to make a healthy bowl
- As a filling for wraps
- Some greens are soup staples and can be added towards the end of cooking to preserve their nutrients
- Can be tossed with noodles and other protein of choice to make stir-fries and sautés
- Can be combined with other healthy fruits and vegetables to make juices and smoothies
- They can be added to other ingredients to make a sandwich filling
- They can be chopped or pureed and added to sauce
- They can be used as substitutes for processed toppings, to make healthy alternatives to pizza
Care must be taken when preparing leafy greens, as blanching, boiling, or cooking can reduce some of their nutrients. High-calorie salad dressing should also be avoided or used sparingly when adopting a healthy diet with leafy greens.
Leafy greens and weight loss
Adding leafy greens to a meal results in consuming fewer calories without increasing hunger. The water content and fibre keep you feeling full for longer, helping you lose weight. Calcium-rich dark leafy green vegetables like kale, spinach, collard green, etc. are great for helping to lose weight. One of the important ways to lose weight is increasing metabolism. High calcium diets have been shown to speed up metabolism by burning more fat. There are several ways of making weight loss-friendly leafy green recipes, but the simple trick is to always ensure you have them washed and ready for use in your refrigerator.
Best practices for including leafy greens in your diet
When selecting vegetables, ensure they have vibrant, fresh, and crisp leaves. Before storing, wash thoroughly and remove outer or damaged leaves. Cold running water is best for washing your greens, special products are not essential as they are unlikely to kill bacteria or mould. Remove excess water with paper towels or a salad spinner before placing the vegetables in an airtight container or plastic resealable bags and then refrigerate.
Common mistakes to avoid
Over-cooking greens leads to a loss of vital nutrients and depletion of essential flavours. Water soluble vitamins like vitamins B and C might be completely lost while some minerals like calcium, iron, and potassium may be reduced by up to 70 percent.5 They are best raw or slightly boiled in low temperatures to get the maximum nutrients from them.
While maintaining a healthy diet for weight management, it is important to not rely only on leafy greens as this is not sustainable, and other classes of food essential for the body will be cut out of your diet. For long-term weight management and overall health, short-term restrictive diets should be avoided. A healthy diet should, therefore, include a good balance of macronutrients – carbohydrates, fat and protein that provide calories for energy, and micronutrients like vitamins and minerals.
Health considerations and allergies
Some green vegetables contain histamine, a chemical that can trigger an allergic response. Some like spinach may also be toxic if consumed excessively. Leafy greens can also carry harmful bacteria like e-coli and must therefore be washed thoroughly before consumption.
Summary
Green leafy vegetables are nutrient-packed foods that offer a range of health benefits including healthy weight management and prevention of some health conditions and are therefore extremely important in healthy diets. However, they must be combined with other classes of food for sustained overall health and well-being. Professional advice should be sought for personalised diet plans or if you have an existing health condition.
References
- Morris MC, Wang Y, Barnes LL, Bennett DA, Dawson-Hughes B, Booth SL. Nutrients and bioactives in green leafy vegetables and cognitive decline. Neurology [Internet]. 2018 Jan 16 [cited 2023 Nov 1];90(3):e214–22. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772164/
- Staff ASN. Most Americans are not getting enough fiber in our diets [Internet]. American Society for Nutrition. 2021 [cited 2023 Nov 2]. Available from: https://nutrition.org/most-americans-are-not-getting-enough-fiber-in-our-diets/
- Current dietary guidelines | dietary guidelines for americans [Internet]. [cited 2023 Nov 2]. Available from: https://www.dietaryguidelines.gov/current-dietary-guidelines
- Knapen MHJ, Jardon KM, Vermeer C. Vitamin K-induced effects on body fat and weight: results from a 3-year vitamin K2 intervention study. Eur J Clin Nutr [Internet]. 2018 Jan [cited 2023 Nov 2];72(1):136–41. Available from: https://www.nature.com/articles/ejcn2017146
- SA, . KMK, . MAS, . MS. Effect of peeling and cooking on nutrients in vegetables. Pakistan J of Nutrition [Internet]. 2003 Apr 15 [cited 2023 Nov 3];2(3):189–91. Available from: https://www.scialert.net/abstract/?doi=pjn.2003.189.191