1.
Longitudinal association of dietary carbohydrate quality with visceral fat deposition and other adiposity indicators.
Zamanillo-Campos, R, Chaplin, A, Romaguera, D, Abete, I, Salas-Salvadó, J, Martín, V, Estruch, R, Vidal, J, Ruiz-Canela, M, Babio, N, et al
Clinical nutrition (Edinburgh, Scotland). 2022;41(10):2264-2274
-
-
-
-
Free full text
Plain language summary
Abdominal obesity, measured by waist circumference, a proxy of visceral fat, is increasing at an even greater rate than overall obesity alone. Diet plays a key role in body fat accumulation; however, recent evidence also indicates that, beyond quantity, the quality of certain nutrients may have an independent effect. The aim of this study was to determine the dynamic association between changes in overall dietary carbohydrate quality and changes in objectively measured visceral and overall adiposity distribution This study is a prospective cohort study based on data collected during the first year of the PREDIMED-Plus (PREvencion con DIeta MEDiterranea Plus) randomised controlled trial. In the PREDIMED-Plus trial, a total of 6874 people were randomly allocated in a 1:1 ratio to either the intervention or control group. Results show that a carbohydrate quality index increase was associated with a decrease in regional and overall adiposity. The observed associations were mostly driven by fibre and the wholegrains/total grains ratio. Authors conclude that the promotion of fibre-rich foods, including fruits, vegetables, legumes and nuts, and the substitution of refined grains by wholegrains, may be important dietary recommendations to adopt in clinical practice to promote a healthier body composition.
Expert Review
Conflicts of interest:
None
Take Home Message:
This prospective cohort of older adults with overweight/obesity and MetS, found that improvements in dietary carbohydrate quality over one year was associated with positive changes in visceral and overall fat deposition, largely due to dietary fibre and the wholegrain/total grain ratio.
Evidence Category:
-
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
X
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Background
Obesity prevalence is increasing worldwide and is associated with a range of metabolic and cardiovascular diseases. Excess visceral fat appears with increasing age but also with unhealthy dietary patterns and lifestyle behaviours, and it contributes to chronic diseases, particularly type 2 diabetes (T2D), insulin resistance, metabolic syndrome (MetS), and cardiovascular diseases (CVD).
Aim
This study determined the association between changes in overall dietary carbohydrate quality and changes in objectively-measured visceral and overall adiposity distribution. Three repeated measurements of diet and adiposity were conducted throughout a 1-year follow-up, using a dual-energy X-ray absorptiometry (DXA) scans for body composition assessment.
The study compared an intensive weight-loss (intervention group) using an energy-reduced Mediterranean Diet (MedDiet), with physical activity (PA), and behavioural support on the prevention of CVD events, compared to usual care and dietary counselling only.
This prospective cohort study analysed a subgroup of 1476 participants (men aged 55-75 years and women aged 60-75 years) enrolled in the PREDIMED-Plus randomized controlled trial. Participants were overweight or obese (BMI>27 kg/m2 and <40 kg/m2) with no previous cardiovascular events and at least three characteristics of metabolic syndrome (MetS): hypertension, hyper-triglyceridemia, lower high-density lipoprotein (HDL) cholesterol, hyperglycemia, or central obesity.
Dietary intake was measured at baseline, 6- and 12-months using a Spanish version of the validated 143-item semi-quantitative food-frequency questionnaire, via face-to-face interviews by trained dietitian-nutritionists. Carbohydrate quality index (CQI) was calculated using four criteria: total dietary fibre, glycemic index, wholegrain/total grain carbohydrate ratio, and solid/total carbohydrate ratio.
Results
Improvements in body composition and lifestyle factors were observed compared to baseline data (both study arms combined) (p < 0.05 for all). A higher Carbohydrate Quality Index CQI (p = 0.024) was observed at both the 6 and 12 month follow-up.
A 3-point increment in CQI over 12-month follow-up was associated with a decrease in visceral fat (β 0.067 z-score, 95% CI -0.088 to -0.046, p<0.001), android-to-gynoid fat ratio* (β -0.038, 95% CI -0.059 to -0.017, p<0.001) (*calculated by dividing the fat mass (g) from the specific regions), and total fat (β -0.064, 95% CI -0.080 to -0.047, p<0.001).
Fibre intake and the ratio of whole grain/total grain showed the strongest inverse associations with all adiposity indicators. Statistically significant differences were observed over time in all CQI components. The most relevant changes were the increase in consumption of carbohydrates from whole-grains and a decrease in refined grains, and an increase in dietary fibre intake. After evaluating each CQI component separately, the study found that fibre intake and the ratio of whole grain/total grain presented the strongest and statistically significant negative associations with all adiposity indicators (all p-values <0.01).
Limitations
Due to the observational nature of the study, causality cannot be inferred. The study population is based on older people with overweight/obesity and MetS from a Mediterranean area, which can limit the generalisability of findings to the general population.
The use of self-reported dietary data is subject to measurement error, where self-reports may be affected by a tendency to respond in a manner to avoid criticism or judgement and to seek social approval.
Clinical practice applications:
Evidence has shown that the quality of dietary carbohydrates, rather than the quantity, may have a greater impact on health and overall mortality.
While visceral fat constitutes only a small proportion of total fat, the available evidence indicates that it plays an important role in certain chronic diseases, such as T2D, MetS, CVD and cancer.
Findings from this study suggest a better CQI via the manipulation of carbohydrate quality may be associated with a decrease in visceral fat, which are independent of changes in total body fat.
Considerations for future research:
Future strategies to decrease visceral fat are warranted.
Robust reference ranges are needed for the interpretation of visceral fat in clinical practice and research settings.
Abstract
BACKGROUND & AIMS The quality of dietary carbohydrates rather than total carbohydrate intake may determine the accumulation of visceral fat; however, to date, few studies have examined the impact of diet on adiposity using specific imaging techniques. Thus, the aim of this prospective study was to investigate the association between concurrent changes in carbohydrate quality index (CQI) and objectively-quantified adiposity distribution over a year. METHODS We analyzed a cohort of 1476 participants aged 55-75 years with overweight/obesity and metabolic syndrome (MetS) from the PREDIMED-Plus randomized controlled trial. Dietary intake information was obtained at baseline, 6- and 12-months from a validated 143-item semi-quantitative food-frequency questionnaire, and CQI (range: 4 to 20) was calculated based on four dietary criteria: total dietary fibre, glycemic index, wholegrain/total grain carbohydrate ratio, and solid/total carbohydrate ratio. Overall and regional adiposity (total body fat, visceral fat and android-to-gynoid fat ratio) was quantified using dual-energy X-ray absorptiometry at all three time points. Multiple adjusted linear mixed-effects models were used to assess associations between concurrent changes in repeatedly measured CQI and adiposity over time. RESULTS After controlling for potential confounding factors, a 3-point increment in CQI over 12-month follow-up was associated with a decrease in visceral fat (β -0.067 z-score, 95% CI -0.088; -0.046, p < 0.001), android-to-gynoid fat ratio (-0.038, -0.059; -0.017, p < 0.001), and total fat (-0.064, -0.080; -0.047, p < 0.001). Fibre intake and the ratio of wholegrain/total grain showed the strongest inverse associations with all adiposity indicators. CONCLUSIONS In this prospective cohort of older adults with overweight/obesity and MetS, we found that improvements in dietary carbohydrate quality over a year were associated with concurrent favorable changes in visceral and overall fat deposition. These associations were mostly driven by dietary fibre and the wholegrain/total grain ratio. TRIAL REGISTRATION The trial was registered at the International Standard Randomized. CONTROLLED TRIAL (ISRCTN http://www.isrctn.com/ISRCTN89898870) with number 89898870 and registration date of 24 July 2014, retrospectively registered.
2.
Targeting body composition in an older population: do changes in movement behaviours matter? Longitudinal analyses in the PREDIMED-Plus trial.
Galmes-Panades, AM, Konieczna, J, Varela-Mato, V, Abete, I, Babio, N, Fiol, M, Antonio de Paz, J, Casas, R, Olbeyra, R, Ruiz-Canela, M, et al
BMC medicine. 2021;19(1):3
-
-
-
Free full text
Expert Review
Conflicts of interest:
None
Take Home Message:
- The importance of including daily physical activity in place of sedentary behaviour.
- The additional benefits of moderate-to vigorous physical activity.
- The importance of seeking medical advice before commencing a physical activity programme
- The importance of working with qualified exercise prescribers when embarking on a new activity programme
Evidence Category:
-
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
X
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Introduction:
Authors highlight that although the relationship between physical activity (PA), sedentary behaviour (SB) and markers of obesity and body composition (BC) have been studied extensively, the balance between PA at different levels of intensity e.g. light physical activity (LPA) intensity and medium to vigorous activity (MVPA) intensity as well as SB in older, obese/overweight adults remains unclear.
Aim and Objectives:
This longitudinal, observational prospective study aimed to explore the relationships between PA and SB in an older population with Metabolic Syndrome (MetS) over a period of 12 weeks (n=1564).
The objectives were specifically to:
1. Evaluate the relationship of concurrent changes in self=reported PA and SB with body composition changes at 12 months using dual-energy X-ray absorptiometry (DEXA).
2. Evaluate the impact of replacing SB with PA at different intensities (LA and MVPA) on BC changes.
Accelerometer-derived inactive time (IT) data was used as a proxy for SB.
Study Design:
The study was nested in the PREDIMED-Plus trial, registered at ISRCTN (89898870). 1564 participants were recruited for the sub-sample (men aged 55-75 n=813; women aged 60-75 n=751) with a BMI >27 and < 40kg/m2 and 3 components of MetS. Data was collected at baseline, 6 and 12 months.
Intervention:
Multicomponent weight loss based on energy restricted Mediterranean Diet (erMedDiet), increasing 30 mins of total PA with behavioural support.
Control:
MedDiet without energy restriction or additional support.
Results:
- At 12 months, participants (intervention and control groups) reduced their waist circumference, BMI, body fat, visceral adipose tissue (VAT) and total energy intake compared to baseline. They increased percentage of muscle mass and muscle-to-fat mass ratio.
- At 6 and 12 months, participants accrued more total PA, LPA and MVPA and less total SB compared to baseline.
After adjustment for potential confounders:
- Increasing 30 min of PA was significantly associated with a decrease in body fat (β − 0.07%, 95% CIs − 0.10; − 0.04%) and VAT (− 13.9 g; − 21.5; − 6.23) and increased muscle mass (0.07%; 0.04; 0.10) and muscle-to-fat mass ratio (0.41; 0.15; 0.67).
- Increasing 30 min of MVPA was linked to significantly reduced body fat (− 0.08%, − 0.11; − 0.04%) and VAT (− 15.6 g; − 24.1; − 7.25) and with increased muscle mass (0.07%; 0.04; 0.10) and muscle-to-fat mass ratio (0.44; 0.15; 0.72).
- Overall, 30 more minutes of total SB was associated with significantly greater body fat and lower muscle mass.
- No significant associations were observed for LPA.
Conclusions:
Increasing PA and substituting SB with PA, in particular MVPA is correlated with improvements in body composition in overweight or obese older adults with MetS.
Clinical practice applications:
- To inform older clients (>55yrs) on the benefits of PA on a range of health conditions e.g. cardiovascular disease and symptoms e.g. metabolic symptoms
- To provide guidance on the benefits of replacing SB with PA, with examples of optimal amount of time and intensity, obviously working within professional boundaries and referring on to relevant experts when necessary
- To encourage practitioners to include recommendations of physical activity as part of a comprehensive approach to physical well-being
Considerations for future research:
- Analyse how increases in physical activity may benefit other chronic health conditions in older adults
- Evaluate how exchanging sedentary behaviour with physical activity may benefit mental health symptoms such as mood and anxiety in adults.
- Explore different facilitators and barriers to increasing physical activity to reduce sedentary behaviour in adults.
Abstract
BACKGROUND The optimal distribution between physical activity (PA) levels and sedentary behaviour (SB) for the greatest benefits for body composition among older adults with overweight/obesity and chronic health conditions remains unclear. We aimed to determine the prospective association between changes in PA and in SB with concurrent changes in body composition and to examine whether reallocating inactive time into different physical activity levels was associated with 12-month change to body composition in older adults. METHODS Longitudinal assessment nested in the PREDIMED-Plus trial. A subsample (n = 1564) of men and women (age 55-75 years) with overweight/obesity and metabolic syndrome from both arms of the PREDIMED-Plus trial was included in the present analysis. Participants were followed up at 6 and 12 months. Physical activity and SB were assessed using validated questionnaires. Out of 1564 participants, 388 wore an accelerometer to objectively measure inactive time and PA over a 7-day period. At each time point, participants' body composition was measured using dual-energy X-ray absorptiometry (DXA). Standard covariate-adjusted and isotemporal substitution modelling were applied to linear mixed-effects models. RESULTS Increasing 30 min of total PA and moderate-to-vigorous physical activity (MVPA) was associated with significant reductions in body fat (β - 0.07% and - 0.08%) and visceral adipose tissue (VAT) (- 13.9 g, and - 15.6 g) at 12 months (all p values < 0.001). Reallocating 30 min of inactive time to MVPA was associated with reductions in body fat and VAT and with an increase in muscle mass and muscle-to-fat mass ratio (all p values < 0.001). CONCLUSIONS At 12 months, increasing total PA and MVPA and reducing total SB and TV-viewing SB were associated with improved body composition in participants with overweight or obesity, and metabolic syndrome. This was also observed when substituting 30 min of inactive time with total PA, LPA and MVPA, with the greatest benefits observed with MVPA. TRIAL REGISTRATION International Standard Randomized Controlled Trial (ISRCTN), 89898870 . Retrospectively registered on 24 July 2014.