Healthy eating, not dieting
The word ‘diet’ comes from the Latin word ‘diaeta’ meaning ‘way of life’. This is in sharp contrast to the way the word is used in today’s society, where it carries connotations of short-term adherence and negative associations with restrictive eating. As such, it is better to prescribe an ‘healthy eating plan’ as opposed to a ‘diet’. If patients embrace an ‘eating for health’ approach to dietary change and do not just view it as a way to lose weight then they may be less likely to ‘give up’ on their diet and start again the next day or week.
Any dietary advice for weight loss should not compromise the person’s micronutrient nutritional status. The types of foods that patients should be eating to lose weight are the same as those that are recommended for the general healthy population. The recommended number of serves in the Australian Guide to Healthy Eating are also based on those with the lowest energy requirements within each age and gender group (i.e. smaller and less active); following the guidelines should inevitably result in an energy deficit for larger persons. These recommendations, developed by the NHMRC, were released in 2015 as part of Eat For Health program (www.eatforhealth.gov.au).
No one-size-fits-all approach
A negative energy balance is essential for weight loss; how such an energy deficit is achieved is dependent on the individual. Weight loss is dynamic and needs to be reviewed on a regular basis. There are dynamic physiological adaptations that manifest with weight loss; namely a reduced resting metabolic rate, increased appetite and decreased energy cost of physical activity.8 Dynamic models that allow prediction of how changes of diet or physical activity will translate into weight changes over time have been developed and are available online (http://bwsimulator.niddk.nih.gov and www.pbrc.edu/research and faculty/ wcalculators/weight-loss-predictor).8,9 These models may be useful in clinical practice to establish a target energy intake for a patient based on the desired weight loss outcome and duration. They can also provide guidance on the energy intake necessary to maintain the new weight once reached.
Temporary changes equal temporary weight loss
Most people who diet reach a weight loss plateau at about six months and this occurs for several reasons. First, people may become less restrictive with their eating, or reduce the time, intensity or frequency of their physical activity and consequently their energy balance is no longer in a deficit. Second, as people lose weight their energy requirements decline. Third, physiological adaptations may occur resulting in a reduction in metabolic rate and increased hunger and food seeking.10-13 At the weight loss plateau people are faced with the following four options (Figure 1):
- return to the way they were eating and exercising (or lack of) before weight loss and therefore regain the weight (the most common scenario)
- maintain their weight by eating and exercising to match their new requirements
- further reduce energy intake and/or increase exercise further to lose more weight
- period of weight maintenance followed by further weight loss (i.e. second option followed by the third).
This introduces several common misconceptions among individuals who have lost weight or are losing weight. First, that they will be able to maintain a lower weight as easily as when they were at a higher weight. Second, that weight plateauing is bad and there is no point in trying if not achieving weight loss. And third, that if you just have a strong enough will power you will be able to decrease your energy intake further and lose more weight.