負卡路里？別做夢了

飲食處處有，但是吃“負卡路里”食物，比如芹菜和葡萄柚，能幫你減肥嗎?

A calorie is a unit of energy, usually expressed as kilocalories (kcal) for the energy content in food. The theory behind negative calorie foods is that some foods have lower calorie (energy) content than the amount of energy it takes to digest and absorb the food into the body. This sounds plausible, in theory. But in reality, even the lowest calorie foods, such as celery, contain more calories than it takes to break down and absorb them in the body.

負卡路里一般是指消耗該食物所需的卡路里比食物本身提供的卡路里要更多。從理論上講，這聽起來似乎有道理，但在現(xiàn)實生活中，即使是最少卡路里的食物，比如芹菜，也是包含比消耗自身所需更多卡路里的。

Our energy needs are made up of three components:

我們的能量需求由三個部分組成：

• The energy needed to maintain a body at rest, which is the energy needed for our body to carry out its basic processes so we can live.

· 維持身體靜止所需的能量，這是我們身體執(zhí)行基本代謝所需的能量，因此我們可以活著.

• The thermic effect of eating, which is the increase in metabolic rate after eating, while food is digested and absorbed.

· 進食的熱效應(yīng)，即進食后代謝率的增加，同時食物被消化吸收.

• Additional energy needed for activity and exercise.

· 活動和鍛煉所需的額外能量.

Of these, the thermic effect uses the fewest calories—about 10% of the energy we take in. In other words, about a tenth of the calories we eat are used to process our food—this includes chewing our food, moving it through the digestive system, absorbing nutrients, and storing excess energy.

其中，進食熱效應(yīng)消耗最少的卡路里 - 約占我們攝入的能量的10%。換句話說，我們吃的卡路里大約十分之一用于處理我們的食物 - 這包括咀嚼我們的食物，將其移動通過消化系統(tǒng)，吸收營養(yǎng)，儲存多余的能量。

Foods such as celery, grapefruit, broccoli, tomatoes, and cucumber have all been touted as negative calorie foods, but there is no scientific evidence to support this idea. Although they are very low calorie foods, with seven to 30 kcal per 100g, it still takes less energy than this to process them. This is because they contain large amounts of water and fiber, which have a very low energy cost.

芹菜、葡萄柚、西蘭花、西紅柿和黃瓜等食品都被吹捧為負卡路里食品，但沒有科學證據(jù)支持這一觀點雖然它們是非常低卡路里的食物，每100克含有7到30千卡熱量，但它仍然需要比這更少的能量來處理自身。這是因為它們含有大量的水和纖維，其能量成本非常低。

Replace, don’t add

換著吃，別多吃

These foods are very useful for people who are trying to lose weight, as they contain a low number of calories. By replacing the food in your diet with some of these—for example, replacing a side portion of chips with a side salad—it is possible to lower your calorie intake considerably. As an extra boost, they are full of nutrients, such as vitamins and minerals, and also contain a lot of fiber, which also has many benefitsfor your health.

這些食物對于試圖減肥的人非常有用，因為它們含有少量的卡路里。通過用這些食物代替原來吃的食物 - 例如，用配菜沙拉替換配菜薯片 - 可以大大降低你的卡路里攝入量。作為額外的助力，它們富含營養(yǎng)素，如維生素和礦物質(zhì)，還含有大量纖維，這對健康也有很多好處。

It’s important to replace higher calorie items on a plate rather than add these fruit and vegetables to meals, as by simply adding healthy items you increase the overall calorie content. For example, a cheeseburger plus a salad contains more calories than a cheeseburger alone.

重要的是把食物中更高卡路里的部分換成更低的，而不是將這些水果和蔬菜添加到膳食中，因為簡單地添加健康食品還是會增加總體卡路里含量。例如，芝士漢堡和沙拉比單獨的芝士漢堡含有更多的卡路里。

In order to lose weight, people need to use up more energy than the energy (calories) they eat and drink, but this is difficult. Research has shown that people tend to underestimate the calorie content of the food they consume, and they underestimate it by more if they are obese rather than normal weight.

為了減肥，人們需要消耗的能量超過他們攝入的能量，但這很難。研究表明，人們傾向于低估他們攝入的食物的卡路里含量，如果他們越肥胖就越會低估。

Researchers have also shown that when people visit fast food chains with a healthier image, they underestimate the calorie content of their meals compared with the same meals at a restaurant with a less healthy image, and may end up consuming more calories overall.

研究人員還表明，當人們?nèi)ゾ哂懈】敌蜗蟮目觳瓦B鎖店時，與低于健康形象的餐廳的同餐相比，他們更低估了他們的膳食中的卡路里含量，并且可能最終消耗更多的卡路里。

Another difficulty is keeping weight off in the long run. Many studies have shown the short-term benefits of diets to help with weight loss, but over 80% of people put the weight back on again over time. In many modern societies, there is easy access to cheap high-calorie foods, so it is difficult to resist high fat/sugar options on a permanent basis.

另一個困難是長期保持體重。許多研究表明飲食有助于減輕體重的短期益處，但超過80%的人會隨著時間的推移重新恢復體重。在現(xiàn)代社會中，很容易獲得廉價的高熱量食物，因此很難長期抵制高脂肪/糖的飲食選擇。

Unfortunately, negative calorie foods are a myth, and there is no easy way to lose weight and keep it off in the long run. Changing your food and drink options for healthier ones on a permanent basis is more likely to lead to sustained long-term weight loss than short-term dieting alone.

不幸的是，負卡路里食物是唬人的，從長遠來看，沒有簡單的減肥方法。長期替換健康食物和飲料的選擇比單獨短期節(jié)食更有可能幫助持續(xù)的長期減重。