“Your body begins to work differently. This study proves that small amounts of nourishment throughout the day are better than the same amount of food concentrated in three big sittings. If we feed the body at regular intervals we send a signal to the body that it doesn’t have to store calories. Conversely, when we skip meals we send just the opposite signal for the body to store calories, creating a negative effect on the metabolism.” — Dr. Wayne Scott Andersen, co-founder and Medical Director at Take Shape For Life
It's been proven by research too: eating attentively was shown to have a direct influence on the amount of food consumed, according to a recent study published in the American Journal of Clinical Nutrition. People who ate a meal while distracted ate a moderate amount more than non-distracted eaters—plus, the distracted eaters ate more food than the non-distracted eaters later in the day. Removing visual information about the amount of food eaten during the meal also led to an increase in the amount of food consumed. The takeaway: The less you focus on your food and the more you focus on the TV/computer/smartphone in front of you, the less satisfied you'll be and the more you'll be inclined to eat now and later. (This isn't the only part your brain plays in your appetite; here's how to trick your brain into healthy eating.)
The main sources of calories in a typical person's diet are carbohydrates, proteins, and fat, with alcohol also being a significant portion of calorie intake for many people (though ideally this should be limited since alcohol contains many empty calories). Some studies have shown that the calories displayed on nutrition labels and the calories actually consumed and retained can vary significantly. This hints at the complex nature of calories and nutrition and is why many conflicting points of view on the "best" methodology for losing weight exist. For example, how a person chews their food has been shown to affect weight loss to some degree; generally speaking, chewing food more increases the number of calories that the body burns during digestion. People that chew more also tend to eat less, since the longer period of time necessary to chew their food allows more time to reach a state of satiety, which results in eating less. However, the effects of how food is chewed and digestion of different foods are not completely understood and it is possible that other factors exist, and thus this information should be taken with a grain of salt (in moderation if weight loss is the goal).