Amongst inactivity, overconsumption of processed foods, and low nutrient intakes, a new culprit has emerged as one of the main contributing factors to obesity in Western populations: increased portion sizes.

 

New research published in the scientific journal of the The Obesity Society has interrogated the effects of portion control in a study examining the effect of prepackaged, portion-controlled meals on overall weight loss.

 

Is our portion control leading to poor weight control? (Photo: Shutterstock)

 

Pre-Packaged Portions for Dietary Intervention

The study assigned 183 study participants to three groups: one that was prescribed two pre-packaged meals per day, one that was prescribed two higher-protein (>25%) pre-packaged meals per day, and a control group who were allowed to select their own meals. All participants met with a dietitian for counselling to determine personal weight-loss goals, received physical activity recommendations, and learned dietary behavioural strategies.

 

After three months, 74% of the study's participants eating the prepackaged foods had achieved weight loss of 5%, compared to only 53% in the control group. The groups that consumed the prepackaged meals also expressed greater confidence in their ability to follow a meal plan long-term.

 

The results of the study showed a meal plan of portion-controlled, prepackaged, frozen meals for lunch and dinner promoted greater weight loss than a self-selected diet. Even better, the subjects with portioned meals reported feeling more motivated and confident to proceed with a lower calorie-intake to facilitate fat loss. As Martin Binks, spokesperson for The Obesity Society commented:

 

"Reduction in energy intake is a key factor to weight loss, but it can be difficult for most individuals with overweight or obesity to put into practice. This type of strategy is a step toward implementing effective, evidence-based solutions to obesity."

 

With the obesity crisis in the West mounting at an alarming rate, it's true that we need solutions, and fast ones. According the World Health Organization, obesity is one of, if not the major risk factor for the most deadly non-communicable diseases, including cardiovascular disease, diabetes, and some cancers.

 

Issues and Limitations

But let's not get ahead of ourselves here. Whilst it's true reduction in energy intake is a key factor to weight loss and overweight populations tend to struggle to stick to a weight loss plan, this study has its limitations.

 

  • The article's abstract provides a disclosure that Nestlé USA supported the study. This should raise an eyebrow in anyone who can see the conflict of interest between a mass producer of processed foods and an 'impartial" clinical research team studying the incidence and treatment of obesity.

 

  • The specifics of each subjects' food intake appears inconsistent. Participants were encouraged to track their food with smartphone apps, but this capture method was not standardized across the study, introducing an overwhelming number of variables into the sample such as finite macronutrient breakdowns, food timing, and food quality - all of which could have affected the participants rate of weight loss.

 

  • The specifics of each subjects' energy balance is too generalized. The research team point out that more weight loss was observed in those assigned to pre-packaged foods overall, but all the participants reported higher activity levels, and it's unclear how these activity levels were measured. If one subject was trying to walk for 10 minutes a day and another was trying out a CrossFit class but both simply reported being "more physically active," a clear uncontrolled variable is at work amongst the data.

 

  • The pre-packaged foods and nutritional counselling were provided without charge to the study's participants. With no cooking or food preparation involved and my grocery bill drastically reduced, I'd be pretty motivated, too.

 

Nothing Beats the Holistic Approach

The obesity situation in the West isn't just a crisis: it's an epidemic. Though the spike in obesity incidence from the mid-1990s to now has slowed, it's still trending upward, and more children are becoming overweight at a younger age. With millions of lives at stake, the temptation to chalk it up to one culprit - in this case, portion control - is overwhelming.

 

But this is the mistake we've made in the past, and one we need to avoid doing again. The vilification of dietary fat has borne a generation addicted to sugar, and if we're not careful, the vilification of sugar will bear a generation that is overly fearful of dietary carbohydrate. The scientific community needs studies like the portion control study to contribute to the wider discourse on obesity and its treatment, but their findings should always be taken with a pinch of salt. (Which, incidentally, is another dietary compound under fire that we can't live without).

 

We should continue to push an attack on obesity that accounts for every major contributing factor, with sensible dietary intervention that covers all of our bases. Portion control wins out in this case, but nothing will supercede the holistic approach of nutrient dense food, macronutrient awareness, and physical activity to fight the onslaught of obesity in our time.

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