In a 2011 study, for instance, people who drank the same 380-calorie(卡路里) milkshake on two separate occasions produced different levels of hunger-related hormones (荷爾蒙), depending on whether the shake's label said it contained 620 or 140 calories.

Hunger levels depend on one's consumption of calories

People tend to take in a lot more calories than necessary.

Choose food with fewer calories

So why not limit the density of food outlets, particularly ones that sell food rich in empty calories?

Among other requirements, they must offer a side dish that meets similar criteria, with fewer than 200 calories and less than 35%of its calories from sugar.

All had the same number of calories over the day, but half had breakfast, while the other half did not.

Cooking real food is the best defense—not to mention that any meal you're likely to eat at home contains about 200 fewer calories than one you would eat in a restaurant.

If you eat three meals a day and behave like most Americans, you probably get at least a third of your daily calories outside the home.

Nearly two-thirds of us grab fast food once a week, and we get almost 25% of our daily calories from snacks.

There have been half-hearted but well-publicized efforts by some food companies to reduce calories in their processed foods, but the Standard American diet is still the polar opposite of the healthy, mostly plant-based diet that just about every expert sa

We wanted to give people an opportunity to actually see the calories before they purchase the food and make a decision, an informed decision that if they want to make a healthier choice, if they want to eat fewer calories, they can.

Energy Usage: Energy is an essential resource across the entire food production cycle, with estimates showing an average of 7-10 calories of input being required in the production of one calorie of food.

This varies dramatically depending on crop, from three calories for plant crops to 35 calories in the production of beef.

Some iced coffees have as many calories as a hot dinner.

Better skip dinner or hit the gym afterwards, with a cancer charity warning that some iced coffees contain as many calories as a hot dinner

The World Cancer Research Fund (WCRF) conducted a survey of iced coffees sold by some popular chains in Britain including Starbucks, Caffe Nero and Costa Coffee to gauge the calories as studies increasingly link obesity with cancer.

The worst offender - a coffee from Starbucks -- had 561 calories

Other iced coffees contained more than 450 calories and the majority had an excess of 200.

Health experts advise that the average woman should consume about 2,000 calories a day and a man about 2,500 calories to maintain a healthy weight.

Dieters aim for 1,000 to 1,500 calories a day

The fact that there is an iced coffee on the market with over a quarter of a woman's daily calories allowance is alarming," Dr Rachel Thompson, science programme manager at London-based WCRF, said in a widely-reported statement.

This is the amount of calories you might expect to have in an evening meal, not in a drink

As a group, "night owl" types tend to eat less healthy food and take in more calories overall than early risers.

For years, nutritionists have recommended that pasta be kept to a minimum, to cut calories, prevent fat build-up and stop blood sugar shooting up.

The later one goes to bed, the more calories one records the next day.

The study also showed that the Mediterranean diet is as high as or higher in fat than other diets, obtaining up to 40% of all its calories from fat.