Data from the Nurses’ Health Study II (NHS II) reveals that yoghurt intake is associated with less weight gain and lower obesity risk in women during the menopausal transition.
The study, which examined the impact of all dairy sources, found that increasing yogurt intake was associated with 0.37-kg lower weight gain (P < 0.001) over four years, whereas no such association was found for other dairy products.
The correlation prevailed even after accounting for other associated lifestyle factors.
This is the first long-term study to investigate the associations of individual dairy foods with weight change in the time surrounding menopause.
The authors, from the Boston University School of Medicine, USA, hypothesise that the mechanisms by which yoghurt may improve weight change and risk of obesity could be as a result of the calcium and probiotic content.
The report states: "Calcium has been postulated to play a role in fat metabolism. Increased calcium intake is reported to inhibit lipogenesis, stimulate lipolysis, promote lipid oxidation, and increase the excretion of fecal fat. Increasing calcium intake has been shown to accelerate weight and fat loss in several studies.
"Although a cup of yogurt has a similar amount of calcium as one cup of milk, yogurt is believed to improve the bioavailability of calcium due to its acidity. Thus, the improved bioavailability may account for the specific weight-reducing effects of yogurt.
"Yogurt is a unique dairy product with a significant abundance of probiotics. Probiotics are live bacteria that boost human health through the digestive system. It has been postulated that probiotics may favorably modulate gut microbiota and prevent against obesity. Moreover, the semisolid matrix of yogurt provides a more satiating feeling and may thus lower hunger."
The authors also note that yogurt intake is an indicator of an overall healthier lifestyle, including more exercise, less smoking, and a healthier general diet but their analysis revealed that the favourable associations of yogurt with prevention of obesity were additive to independent associations of physical activity and AHEI (Alternative Healthy Eating Index) scores.
Menopausal weight gain
Results from the Healthy Women Study, a longitudinal observational study, revealed that women gained 2.25 kg on average during
the three years of the menopausal transition; 20% of them gained more than 4.5 kg.
The Study of Women’s Health Across the Nation also showed a 10% increase in fat mass among women transitioning to menopause. In addition to weight gain, studies indicated that the menopausal transition contributes to a shift in body fat distribution, leading to more central fat accumulation which could further increase risk of diabetes, or CVD, and metabolic syndrome (MetS) in perimenopausal women.
The NHS II was launched in June 1989, with the enrolment of 116,429 registered nurses aged 25–42 y. On the first questionnaire, participants were asked to provide information on their medical history, anthropometrics, and lifestyle factors.
Every two years after, a follow-up questionnaire was sent to participants to update their data and to identify incident diagnoses of the disease.
The first FFQ was sent in 1991 and subsequent FFQs were sent every four years. The response rate to questionnaires was approximately 85%–90%.
In their analysis, the researchers included data on participants from 1989 to 2015, although the focus of the analysis for each individual was around 12 years around menopause.
There are some limitations of this study. First, the use of the FFQ and self reported weight could lead to participant error. Another limitation is the generally low level of consumption of yogurt in this cohort. Therefore, the authors say further studies are warranted to determine whether a higher level (e.g., 1 s/d) of yogurt consumption would still show beneficial associations with weight change.
Moreover, the lack of information on the sugar content of yogurt prevented the researchers from separating yogurt with added sugar from those without added sugar. Finally, NHS II participants were largely Caucasian nurses with higher education levels. These women may be more health-conscious than the general population of perimenopausal women, which could lead to some biased reporting and also limit the generalizability of these results.
Source: Journal of Nutrition
"Dairy Foods, Weight Change, and Risk of Obesity During the Menopausal Transition"
Yuan. M., et al