Pasta-rich diet may 'prevent pounds from piling on',...

"Pasta DOESN'T make you fat – it actually helps weight loss," the Daily Mail reports. In the latest round of the nutrition wars, carbs are fighting back, with a study showing that a diet rich in pasta was linked to lower body mass index (BMI).

The researchers used survey data and body measurements taken from over 23,000 Italian adults and found that pasta, as part of a healthy Mediterranean diet, is associated with lower BMI and smaller waist circumference and waist-to-hip ratio.

The researchers speculate that healthy amounts of pasta may make people feel fuller so they are less likely to stray or snack outside their recommended diet.

Before we reach for the rigatoni, it is important to note the study's limitations.

The researchers attempted to adjust variables that might be responsible for the link, such as the level of physical activity, however this is always an educated guess. Also, as this was an entirely Italian-born, white population we don't know if similar findings would be seen in other populations.

Overall this study tells us that eating pasta as part of a nutritious Mediterranean diet may be a good way to maintain a healthy weight and shape.

Despite frequent media claims to the contrary, there is no such thing as a magic food type – be it carbs, fats or proteins – that will make or keep you thin.

How much you eat, in terms of calories, is far more important than what you eat, when it comes to preventing obesity.

Where did the story come from?

The study was carried out by researchers from the Istituto Neurologico Mediterraneo Neuromed in Italy.

Funding for the Moli-sani study was provided by the Pfizer Foundation, the Italian Ministry of University and Research-Programma Triennale di Ricerca, and Instrumentation Laboratory. While funding for the INHES study was provided by Barilla and by the Italian Ministry of Economic Development.

While many newspapers highlighted the fact that this was an Italian study (Italy being the land of pasta) there were no conflicts of interest reported.

The study was published in the peer-reviewed journal Nutrition & Diabetes on an open-access basis so you can read it for free online.

This story has been reported enthusiastically in the media, however stating that pasta can make you slim is a step too far. Many reports have mentioned that carbohydrates have been demonised in recent times (mainly by the same newspapers now reporting this study) and it is important to reassure that they can be enjoyed as part of a healthy balanced diet.

What kind of research was this?

This was an analysis of two cohort studies that aimed to assess the link between pasta intake and body mass index (BMI) and waist-to-hip ratio.

The researchers used data from two large Italian cohorts to further investigate the Mediterranean diet as a model for healthy eating. Pasta is a popular component of the diet, but as it has not been studied in detail the team wanted to investigate further.

What did the research involve?

The researchers used data from two large cohorts to investigate the association between pasta intake and BMI and waist to hip ratio.

The Moli-sani study recruited participants between March 2005 and April 2010 from the Molise region in Italy. Participants were required to complete a food frequency questionnaire adapted for an Italian population. The questionnaire was used to determine their nutritional intake during the previous year. They only included white people born in Italy, and excluded those with incomplete medical or dietary questionnaires and those on a special diet.

The Italian Nutrition and Health Survey (INHES) was a telephone-based survey that took place between November 2010 and November 2013. The survey was designed to collect information on dietary habits and participants reported on their food and drink consumption in the previous 24 hours using computer software.

Data collected from the surveys was used to analyse pasta consumption (calculated as grams per day and grams/kcal of total daily energy intake), as well as adherence to a Mediterranean diet (on a score from 0 (low) to 11 (high)). The researchers also collected information on socioeconomic status and level of physical activity. Bodyweight, height and waist/hip circumference were measured in the Moli-sani population and self-reported in the INHES population.

Statistical modelling was used to evaluate the link between pasta consumption and BMI and waist-to-hip ratio, adjusting for potential confounders.

What were the basic results?

A total of 14,402 adults (35 years and over) were included from the Moli-sani cohort and 8,964 from the INHES study (18 years and over).

Analyses in the Moli-sani population found that increased pasta consumption was associated with increased BMI. Pasta consumption was also associated with greater adherence to the Mediterranean diet. When the analysis was adjusted for possible confounders, including the greater Mediterranean diet adherence, the association changed direction and greater pasta intake was linked with reduced BMI.

In the INHES study, consuming higher quantities of pasta was associated with higher BMI in women, but not in men. However, similarly adjusting for confounders reversed the link.

In the Moli-sani study, higher quantities of pasta were associated with smaller waist and hip circumference and waist-to-hip ratio in both genders.

How did the researchers interpret the results?

The researchers conclude: "As a traditional component of MeD [Mediterranean diet], pasta consumption was negatively associated with BMI, waist circumference and waist-to-hip ratio and with a lower prevalence of overweight and obesity."

Conclusion

This analysis of data collected from two Italian cohorts has assessed the link between pasta intake, BMI and waist-to-hip ratio.

It seemed initially that higher pasta consumption was associated with higher BMI – as may be expected. However, when you took into account this being a component of a Mediterranean diet, the link reversed and it was associated with lower BMI, smaller waist and hip circumference and waist-to-hip ratio.

While these findings sound great it is important to consider the limitations of the research.

The population being considered are from Italy and were mainly Caucasian, so we don't know if similar findings would be seen in other populations. This is an important limitation – particularly given that adherence to the Mediterranean diet seemed to have a significant influence on the effect of pasta intake on BMI. Higher intakes of vegetables, olive oil, lean meat and fish may be contributing to the healthier bodyweight – not just the pasta.
There were a large number of potential participants in the Moli-sani study who were excluded due to incomplete medical or dietary questionnaires – over 2,000 people. Depending on their consumption and body measurements, this may affect findings.
The researchers attempted to adjust for possible confounders, such as physical activity and energy intake, however this will never be perfect. Residual confounding could still be having an effect and may be responsible for the negative association seen.
Self-reported data – as is the case with all food frequency assessments – is always subject to bias. In the INHES study, participants were also asked to measure their own bodyweight and height, which may not have been accurate.

The study does have strengths in its large sample size and the careful analysis that aimed to adjust for potential sources of error, such as the possible bias from underreporting of energy intake.

Overall this study tells us that eating pasta as part of a nutritious Mediterranean diet may be a good way to maintain a healthy bodyweight and waist-to-hip ratio. That being said, when it comes to diet the best approach is to consume energy-dense products, such as pasta, in moderation.

Read more advice about eating a balanced diet.