Can fruits and vegetables help people lose weight? Correct eating methods and common misconceptions.

Can fruits and vegetables help people lose weight?

How should one plan their diet during weight loss? Most people would answer, "I would force myself to eat as little as possible, or even not eat at all." For dieters, one of the most painful things in life is having to endure hunger frequently.

Enduring hunger is never a pleasant experience; it robs one of the joy of life. Worse still, hunger can cause a surge in appetite, leading to intense cravings for high-carbohydrate foods like sweets and bread, and an inability to resist rich, greasy meals. Once appetite is disrupted, it often results in regrettable indulgence, followed by weight rebound.

Fruits and vegetables are low in energy density and high in dietary fiber. Making good use of fruits and vegetables can effectively help people avoid hunger during weight loss.

A meta-analysis of 12 randomized controlled human studies on increasing fruit and vegetable intake found that increasing fruit and vegetable intake led to an increase in the proportion of energy derived from carbohydrates, a decrease in the proportion derived from fat, an increase in dietary fiber intake, and an increase in the intake of antioxidants.

Studies show that consuming fruit can reduce the risk of obesity in adult women and help slow weight gain in overweight adults. Replacing snacks such as desserts, cookies, and cakes with low-glycemic index fruits like pears or apples is beneficial for weight loss.

Studies using the Mediterranean diet to help participants lose weight have found that increasing vegetable intake and reducing sweets intake can lead to successful weight loss over six months. Vegetables increase food volume, improving satiety, and slow down digestion, helping to control the rate of post-meal blood sugar spikes, thus contributing to successful weight loss.

However, some studies have shown that increasing fruit and vegetable intake does not necessarily lead to significant weight loss.

A systematic review categorized intervention studies on the relationship between fruit and vegetable intake and body weight. The first category of studies took various measures to encourage or support people to eat more fruits and vegetables; the second category of studies directly provided a certain amount of fruits and vegetables for people to consume daily.

A meta-analysis of the two types of studies revealed that the weight loss effect was slightly more pronounced in the first type of study compared to the second. However, even so, the effect was not significant enough. In terms of energy intake, both types of studies showed a slight increase in total energy intake after consuming more fruits and vegetables, with the second type showing a larger increase (approximately 46 kcal per day in the first type and approximately 180 kcal per day in the second type).

Researchers say that simply encouraging people to increase their fruit and vegetable intake, without emphasizing that fruits and vegetables should replace other foods, often leads people to overeat on top of their existing diet. This likely won't result in weight loss, as fruits and vegetables, especially fruits, also contain energy. Fruits and vegetables are not weight-loss drugs; they won't make you thin instantly.

It's important to note that the benefits of vegetables for weight loss depend on cooking with minimal oil. Otherwise, the large amounts of fat consumed from cooking oil and salad dressings can negate or even reverse the benefits of eating vegetables. This may explain why many epidemiological studies have failed to find evidence that eating more vegetables helps with weight loss.

How to make vegetables help you lose weight easily

As mentioned earlier, eating fruits and vegetables doesn't necessarily lead to weight loss. Is it possible to find a clever way to eat vegetables that doesn't require much oil and salt, yet helps people naturally reduce their calorie intake, thus gradually leading to weight loss?

A study by South Korean scientists has provided us with a helpful insight.

They considered that Asians are accustomed to eating rice as their staple food, and if they eat less rice, they will feel like they are dieting and will easily feel hungry. So, they came up with an idea: to "add something fake" to the rice. They chopped up fresh radish greens and other vegetables, mixed them with the rice, and cooked them in a rice cooker to make "vegetable rice".

Radish greens are a leafy green vegetable, high in dietary fiber, high in water content, and low in energy. With radish greens added, the energy content of the rice dish is significantly lower than that of white rice of the same weight, yet it doesn't appear to be less in the bowl. In fact, because of the larger gaps between the leaves, 100 grams of rice cooked with radish greens appears to have a larger volume, and the amount of starch in a bowl of rice is reduced.

Researchers selected 30 healthy women with normal appetite and digestive abilities as subjects for the study.

On the first day at noon, participants were asked to eat a fixed amount of rice and vegetables, along with their usual side dishes. Several hours later, a buffet dinner containing rice was provided. Researchers secretly recorded the types and quantities of food each participant ate at dinner and then calculated the energy content.

On the second day at noon, the participants were asked to eat the same weight of regular rice as the previous day, along with the same side dishes. Then, they were provided with the same buffet dinner as the previous day, and the types and quantities of food consumed by each participant were recorded.

Researchers found that although the total energy intake at lunch was less when eating the same weight of mixed rice and vegetables compared to eating regular rice, the participants did not feel hungry and even felt fuller. This effect continued into the next meal, and the participants ate significantly less at dinner. Calculations showed that eating mixed rice and vegetables as the main dish resulted in significantly lower energy intake at the evening buffet compared to eating regular rice.

Why does cooking rice with leafy greens have such a significant effect? ​​It's likely because vegetables contain a lot of water, and their energy density (energy per unit weight or volume) is much lower than that of rice. Reducing energy intake helps control weight.

When eating, most people focus on the weight of food they consume, not the amount of energy they take in. The stomach works similarly; it feels full when it perceives sufficient volume of food, rather than accurately determining that it hasn't eaten enough simply because the food contains a higher water content. Therefore, although the vegetable-rice dish has a lower energy density, compared to the same weight of regular rice, the participants felt they had eaten a full bowl of rice; in fact, because the vegetable-rice dish has a larger volume than regular rice, the participants subconsciously perceived that they had eaten more, and the feeling of stomach distension misled their bodies into thinking they were fuller.

You might say, "It's too much trouble to chop up the vegetables and mix them into the rice. Why not just eat some stir-fried vegetables with the rice?" The answer is: the latter may not be as effective as the former.

South Korean scientists have discovered that in a rice-based diet, the total energy intake in a meal depends on the energy density of the rice. In other words, Asians are accustomed to judging whether they have eaten enough by "how much rice they have eaten." If vegetables are only eaten as side dishes and not mixed with rice, it is difficult to achieve the effect of eating less rice without feeling hungry, and it is also difficult to achieve the effect of reduced appetite and energy intake at the next meal.

Therefore, cooking vegetables, especially leafy greens high in dietary fiber, together with rice may be a simple way to enjoy the feeling of fullness while controlling weight during weight loss. In fact, most people don't consume enough leafy green vegetables daily. Dark green leafy vegetables are rich in vitamins, minerals, phytochemicals, and nitrates that help control blood pressure, offering numerous health benefits. Cooking them with rice can help prevent diseases such as diabetes, high blood pressure, coronary heart disease, and stroke, while also reducing the risk of malnutrition during weight loss.

Of course, depending on personal preference, radish greens can be replaced with other vegetables, such as celery leaves, kale leaves, wormwood stalks, or bok choy. Adding diced mushrooms or shredded kelp not only provides soluble dietary fiber but also enhances the umami flavor.

Speaking of this, we must mention one of the healthiest Chinese dishes – steamed vegetables, or "wheat rice." It's made by mixing various vegetables like celery leaves and wormwood stalks with a small amount of flour or cornmeal, then steaming them together. Steamed vegetables can be eaten as a side dish or a main course. Served with a garlic and vinegar sauce with a few drops of sesame oil, it's incredibly satisfying and provides a feeling of fullness with very low calories. It's a great low-calorie, high-satiety food for dieters and a good way for people with chronic illnesses to supplement their vegetable intake.

Laboratory studies have found that compared to eating only a bowl of rice without vegetables, simply eating half a bowl of lightly cooked leafy green vegetables (about 100 grams) before a meal, plus the 200 grams of vegetables consumed with each bite of rice, can effectively increase satiety and make one less likely to feel hungry after a meal. This is a simple and effective way to prevent hunger for those trying to lose weight.

In short, weight loss should not be achieved through starvation dieting. Instead, one should adopt smart and healthy eating habits, take care of the body's feelings and nutritional needs, naturally control appetite, and lose excess fat without even realizing it.

Of course, this method of increasing vegetable intake is not a quick way to lose weight; it is a sustainable approach that is also very helpful in maintaining a good figure after successful weight loss.