This article is reproduced from the "China Biotechnology Network" WeChat public account.
Nowadays, more and more people are becoming more and more "inflated" uncontrollably. Worldwide, hundreds of millions of adults and children have been clinically diagnosed with obesity. "Fivesomes, there must be two fat people" is the current situation of the global population. At the same time, the Internet has become the public's main source of access to nutrition and health-related information. Of course, it is also full of various "tricks" for rapid weight loss.
Obesity is known to be an energy imbalance caused by long-term calorie intake exceeding energy expenditure. Therefore, "keeping your mouth shut" (controlling diet structure and food intake) and "opening your legs" (developing the habit of exercising) are always the most effective and safest ways to lose weight. But in the face of perseverance, many people have lost and instead opted for some more compliant methods.
Last year, a study published in Nutrition using Google Trends to survey public interest in a variety of diets showed that vegan, vegetarian and gluten-free diets were the most popular, and they attracted the greatest public interest globally.
The high-protein diet that was at the top of the list more than a decade ago has fallen to the last place, showing that the global public has realized the health threat posed by obesity. However, the survey also found a diet that we are "less familiar with," the "negative calorie" diet. In recent years, this good diet seems to have become a popular meal in the weight loss industry.
The so-called negative-calorie diet refers to the processing (digestion, absorption, transportation, metabolism and storage of ingested nutrients) required more energy than the energy contained in the diet. In short, eating these foods allows you to reduce calories even more.
Food provides our bodies with the nutrients it needs, we consume calories by eating, and we burn calories by burning energy. Our energy needs are composed of three parts: 1, the energy required by the body in a resting state; 2, the eating heat effect, that is, the metabolic rate increases after eating, while the food is digested and absorbed; 3, the additional energy required for physical activity.
Some diets that have been labeled "negative calories" include celery, grapefruit, tomatoes, cucumbers, broccoli, lettuce, and carrots, which are usually fruits and vegetables with high water content. Cold water and chewing gum are also labeled as "negative calories."
According to its meaning, eating these foods will make us consume more calories than not eating, isn't this beautiful, beautiful, beautiful! Is this reliable?
Here are the views of three nutrition and physiologists on this:
Dr Louise Dunford, expert in nutrition and physiology at De Monfort University in the UK: Unlikely
There is no scientific evidence to support this view. In theory, this sounds like a point. But in reality, even the lowest calorie foods, such as celery, tomatoes, and cucumbers, contain 7 to 30 kilocalories per 100 grams, more than the body needs to break down and absorb them.
Tim Crowe, nutritionist at Thinking Nutrition: Extremely unlikely
There is no evidence of the existence of a negative calorie diet. Even the humble celery, although it is about 95% water, still contains a small amount of calories from carbohydrates, 65 kJ per 100 grams to be precise. Although digesting food consumes energy, that is, the thermal effect of food, this is equivalent to about 10% of the energy contained in food. So even celery can add calories to your diet. Although this is a small number, it is definitely not a negative number.
Cornelie Nienaber-Rousseau, nutrition expert at North West University in South Africa: Not sure
Water contains no energy, and when drinking water outside the body temperature range, it consumes some energy to maintain body temperature, the so-called water-induced thermogenic effect. Several studies have tried to explore whether this effect is beneficial for weight loss, but most have found that after drinking cold water, calories are burned little or no. The effect of chewing gum is also very small. Chewing consumes only 11 kilocalors (46.2 kJ) per hour, so it is difficult to be considered a real sport. Because a piece of gum contains about 10 kilocalories (42.0 kJ) of calories, it takes more than an hour to chew to consume the energy provided by the gum.
"Are there other benefits to the so-called 'negative calorie' diet?"
If celery, grapefruit, and cucumber don't cause us to lose calories, why do they often appear in effective weight loss recipes?
Nienaber-Rousseau said: "These so-called negative calorie foods contribute to weight loss not because they lead to insufficient energy intake, but because they fill the stomach with foods with low energy density to satisfy hunger, plus exercise can lead to burning more calories than they ingest, resulting in an overall reduction in energy." ”
Crowe adds: "If your mouth is stuffed with celery, you don't have room for burgers and fries. "Therefore, eating so-called 'negative calorie' foods can make you feel full, which can help you lose weight." However, it is important not to think that adding these foods to the diet will be all right.
"It's important to replace the high-calorie foods in your diet with fruits and vegetables, rather than just adding fruits and vegetables to your pre-existing diet, because it will only make you consume more calories overall," Dunford said. For example, a cheeseburger plus a salad contains more calories than a cheeseburger. ”
Interestingly, this is psychologically difficult to do. Nienaber Rousseau notes, "Studies have shown that when healthy foods like zero-fat foods are present, people underestimate the energy content of foods. This phenomenon is called the 'negative heat illusion'. ”
Dunford concludes: "Unfortunately, negative calorie foods are just a legend, and there are no shortcuts to losing weight and maintaining weight for the long term. Permanently choosing a healthier diet will contribute to long-term weight loss and good health compared to a simple short-term diet. ”
In 2022, should we take a longer-term view, take care of our health while "working hard and doing not slackening" to meet a more distant and better future.
End
Resources:
[1] Kamiński M, Skonieczna- ydecka K, Nowak JK, Stachowska E. Global and local diet popularity rankings, their secular trends, and seasonal variation in Google Trends data. Nutrition. 2020 Nov-Dec;79-80:110759. doi: 10.1016/j.nut.2020.110759. Epub 2020 Feb 12. PMID: 32563767.
[2] Do 'negative-calorie' foods exist? https://metafact.io/factchecks/1787-do-negative-calorie-foods-exist