Flexible dieters are more successful dieters: weight regain and the tendency to think in black and white terms

Maintenance of a healthy body weight is challenging for many people. Diet success rates are generally low and it has been shown that 50% of the weight loss is usually regained after one year. 

A factor that has been associated with overeating and weight regain is thinking in black and white terms; a personality trait that is called dichotomous thinking. People often hold divided beliefs about food (healthy or unhealthy), their diets (on track or out of track), but also about their weight (acceptable or unacceptable) and these beliefs may lead them to overeating when they have the feeling that they have violated their diet.  

Katerina Palascha

For her Master thesis project, Katerina Palascha conducted a survey among 241 adults. She wrote a paper about the study and recently this paper was published  in Journal of Health Psychology. Quite an achievement!

The study revealed that the greater the self-initiated attempt to control food intake (dietary restraint) the higher the weight regain. However, it was the dichotomous thinking rather than dietary restraint that really predicted weight regain. This implies that when the attempt to control intake is accompanied by a rigid ‘black and white thinking’ style, people’s ability to control their food intake may be inhibited, thus leading to weight regain. In line with this finding, a study of Sairanen and colleagues showed that adopting a more flexible self-restrictive eating behaviour (as opposed to rigid self-restriction) could lead to a better weight loss maintenance and well-being.

Katerina's study again showed the importance of avoiding the 'what the hell' effect. Do not think: 'I have already ruined my diet for today, why not even indulge more..!'. Flexible dieters are more successful dieters.

Why 'black and white' thinking makes you eat more

Many dieters who lose a lot of body weight will be back where they started or even heavier. Some dieters, however, manage to keep off some or all the weight. In a study of Susan Byrne and colleagues, aimed to learn more about successful and failing dieters, the most powerful psychological predictor of weight regain was a dichotomous thinking style. This thinking style is also called 'black and white' or 'all or nothing' thinking. Dieters think they have to eat perfectly or do nothing at all.

Dose insensitivity

Not only dieters, but many consumers label foods as either 'good for health' or 'bad for health', without any options in between and regardless of the amount eaten. In a survey of Paul Rozin and colleagues, 40% of the respondents agreed with the statement 'Although there are some exceptions, most foods are either good or bad for health'. They call this tendency to believe that something in large amounts is also harmful in small amounts 'dose insensitivity'.

People overgeneralize even to the level of gaining weight from eating foods. In a study of Michael Oakes and Carole Slotterback, participants were presented with food and their caloric content. One of their fascinating findings? One bag of potato chips (152 calories) was judged to promote more weight gain than a large raisin bran muffin (460 calories).

Venco Zwart-witjes Liquorice - good or bad?

The advantage of this thinking style is that it makes life simple and reduces the number of choices you have to make. You chose a 'good food' and you can eat how much you want, without worrying about gaining weight. Perhaps this tendency is not surprising as consumers are bombarded with advertising and claims focusing on benefits of consuming one food or meal. Perhaps even some over simplistic nutrition education campaigns can partly be blamed ('beware of fat').

This 'black and white' mind-set can make you overeat. No matter how large the portion size, you are likely to underestimate your calories and as a result overindulge. Dieters thinking 'black and white' also talk negative to themselves. Once they break a diet rule, pessimistic thoughts come up, such as: 'Now I have blown it; I ate three chocolates, I might as well finish the entire box' or 'this is not a dieting day anymore...'.  Consequently, they do not stop eating and ignore physical feelings of fullness ('what the hell effect').

Do you agree with the statement: 'I don't want to give up the foods I like'?

I do, and I am not alone in this. In a survey of the Academy of Nutrition and Dietetics, 82% of the respondents agreed with this statement. It is hard to abandon foods from your life that you really love. Tell yourself 'you can't eat that!', and the more tempting it becomes. It may help to identify such thinking patterns and replace them with a more realistic view on eating. For example, enjoy a little snack, just don't go overboard.