Generally, you need to cut calorie intake by 3,500 calories per week to use a pound. Therefore, a portion-controlled lunch five times a week could be an easy way to weight loss. For example, forgo crisps, cakes and snacks with your sandwich to save up to 500-700 calories, equating to a pound a week weight loss.
In a study published in the journal Appetite, 17 volunteers ate whatever they wanted from a buffet for one week. For the next two weeks, half the group selected their lunch by choosing from one of six commercially available, portion-controlled foods, but could eat as much as they wished at other meals or snacks. For the final two weeks, the other half of volunteers followed the same regime.
While eating portion-controlled lunches, each study participant consumed 250 fewer calories per day and lost, on average, 1.1 pounds.
"Making small reductions in energy intake to compensate for the increasing number of calories available in our food environment may help prevent further weight gain, and one way of doing this could be to consume portion-controlled lunches a few times a week," said doctoral student Carly Pacanowski, who co-authored the study.