An examination of the impact of unmelted, melted, and deconstructed cheese on lipid metabolism: a 6-week randomised trial.

Background: Evidence suggests cheese has a favourable or neutral effect on cardiometabolic health, compared to butter. To date, studies have only considered the cheese matrix in its unmelted form, while the effect of melted cheese remains unknown. Objective: To test the effect of 6-week daily consumption of ∼40 g dairy fat, eaten in either as unmelted cheese, melted cheese, or in a fully deconstructed form, on markers of metabolic health in overweight adults aged ≥50 years of age. Design: A 6-week randomised parallel intervention, where 162 participants (43.3% male) received ∼40 g of dairy fat per day, in 1 of 3 treatments: (A) 120 g full-fat Irish grass-fed cheddar cheese, eaten in unmelted form (n 58); (B) 120 g full-fat Irish grass-fed cheddar cheese eaten in melted form (n 53); or (C) the equivalent components; butter (49 g), calcium caseinate powder (30 g), and Ca supplement (CaCO3; 500 mg) (n 51). Results: There was no difference in weight, fasting glucose, or insulin between the groups post-intervention. Melted cheese, compared to unmelted cheese, increased total cholesterol (0.23 ± 0.79 mmol L-1vs. 0.02 ± 0.67 mmol L-1, P = 0.008) and triglyceride concentrations (0.17 ± 0.39 mmol L-1vs. 0.00 ± 0.42 mmol L-1, P = 0.016). Melted cheese increased total cholesterol concentrations by 0.20 ± 0.15 mmol L-1 and triglyceride concentrations by 0.17 ± 0.08 mmol L-1 compared to unmelted cheese. No significant differences were observed between the cheese forms for change in HDL, LDL or VLDL cholesterol. Conclusion: Compared to unmelted cheese, melted cheese was found to increase total cholesterol and triglyceride concentrations in middle-aged, overweight adults with no effect on weight or glycaemic control.

A food-exchange model for achieving the recommended dietary intakes for saturated fat in Irish children: analysis from the cross-sectional National Children's Food Survey II.

OBJECTIVE: To identify the main foods determining SFA intakes and model the impact of food exchanges to improve compliance with dietary fat recommendations in Irish children. DESIGN: Estimated food and nutrient intakes were obtained from a cross-sectional study, the National Children's Food Survey II. Participants were categorised into low, medium and high SFA consumers, and the contribution of food categories to SFA intakes was compared. A food-exchange model was developed, whereby a selected range of high SFA foods was exchanged with lower SFA or unsaturated fat alternatives. SETTING: Participants were randomly selected from primary schools throughout the Republic of Ireland. PARTICIPANTS: A representative sample of 600 Irish children (5-12 years). RESULTS: The main determinants of low and high SFA consumers were milk, cheese and butter. These foods, including snack foods and meat and meat products, were considered exchangeable foods within the model. Compared with baseline data, modelled intakes for total fat, SFA, MUFA and trans-fat presented decreases of 3·2, 2·7, 1·6 and < 0·1 % of total energy (% TE), respectively. PUFA, n-6, n-3 and alpha-linolenic acid showed increases of 1·0, 0·8, 0·2 and 0·1 % TE, respectively. Compliance with total fat, MUFA and trans-fat recommendations remained adequate (100 %). Adherence to SFA and PUFA recommendations improved from 18 to 63 % and 80 to 100 %, respectively. CONCLUSION: The food-exchange model decreased SFA intakes and increased PUFA intakes, suggesting modest dietary changes to children's diets can effectively improve their overall dietary fat profile.

Dairy consumption in adults in China: a systematic review.

BACKGROUND: Research on dairy consumption in China is lacking, however, some evidence has demonstrated significant changes in recent years, with a reported increase in the overall consumption of dairy products. To fully understand these changes, a systematic review was conducted to examine reported dairy intakes and differences between dairy consumption in different population groups in China. METHODS: Web of Science, Embase, and PubMed databases were searched for studies published from January 2000 to September 2022. The China National Knowledge Infrastructure (CNKI) was used to retrieve papers available in Chinese. Papers reporting dietary intakes of dairy consumption across age, sex, and geographical location sub-groups were considered for inclusion in this review. In addition, this review includes the consumption of different types of dairy foods and changes in dairy intake over time. RESULTS: Forty-seven papers were included in the present study. Twelve papers examined dairy consumption across age groups, showing that middle-aged adults tend to consume less dairy than other age groups. Studies comparing across location-specific cohorts reported dairy intakes among urban populations were higher than rural, as well as being higher than the national average. Coastal, Northern and Eastern residents consumed more dairy products than those living in other regions of China, and people in larger cities had higher reported intakes than smaller cities. Milk was the primary dairy product reportedly consumed by Chinese population, followed by yogurt. Concerning sex, evidence showed that females generally reported a greater daily dairy intake than males. CONCLUSIONS: This review shows that, in China, several different population groups displayed significant differences in the amount and type of dairy consumed. When considering the incorporation of dairy products into healthy eating guidelines or positioning specific dairy products on the market, it is important to consider the differences and variations in consumption patterns within population groups.

Determination of factors associated with serum cholesterol response to dairy fat consumption in overweight adults: Secondary analysis from an RCT.

Elevated intakes of saturated fatty acids (SFA) can adversely affect serum cholesterol levels. Dairy fat contains ~60% SFA, prompting healthy eating guidelines to recommend low-fat dairy. Physiological, and environmental factors influence inter-individual variance in response to food consumption. Evidence exploring the dairy matrix has differing effects of dairy fat consumption on serum cholesterol levels when consumed in the form of cheese. The extent of this variability and determinants of response to dairy fat are currently unknown. The objective of this study was to determine factors associated with lipid metabolism response to a dairy fat intervention, with a focus on serum cholesterol. A 6-week randomized parallel intervention trial was carried out in healthy volunteers (≥50 years, BMI ≥25 kg/m2). Participants (n = 104) consumed ~40 g dairy fat daily in addition to their usual diet, in 1 of 3 forms: butter, cheese, or reduced-fat cheese and butter. For this analysis, "response" was based on the percentage (%) change in serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) from pre- to post-intervention. Participants were divided into tertiles for each lipid response. The upper and lower tertiles were used to categorize participants as "responders" and "non-responders." For TC and LDL-c, response was classified as a decrease, whereas "response" was defined as an increase for HDL-c. Clinical response was also considered, by calculating pre- and post-intervention prevalence of those meeting target levels of cholesterol recommendations. Participants demonstrating the largest % decrease (Tertile 1; "responders") in TC had significantly higher levels of TC and HDL-c, at baseline, and lower levels of triglycerides (TAGs) compared to those in tertile 3 (i.e., TC non-responders). Those with the largest % decrease in LDL-c (Tertile 1: LDL-c responders) had higher baseline levels of LDL-c and lower levels of TAGs. Multiple regression analysis revealed that the % change in TC and LDL-c was associated with baseline TC, TAG, body weight and high-sensitivity C-reactive protein (hsCRP; P < 0.05). Previous work has demonstrated the dairy food matrix affects lipid response to dairy consumption. This study suggests that phenotypic differences may also influence response to dairy fat in overweight individuals.

Dietary fat intakes in Irish children: changes between 2005 and 2019.

OBJECTIVE: To examine current dietary fat intakes and compliance in Irish children and to examine changes in intakes from 2005 to 2019. DESIGN: Analyses were based on data from the Irish National Children's Food Survey (NCFS) and the NSFS II, two cross-sectional studies that collected detailed food and beverage intake data through 7-day and 4-day weighed food diaries, respectively. SETTING: NCFS and NCFS II, Republic of Ireland. PARTICIPANTS: A nationally representative sample of 594 (NCFS) and 600 (NCFS II) children aged 5-12 years. Current intakes from the NCFS II were compared with those previously reported in the NCFS (www.iuna.net). RESULTS: Current intakes of total fat, SFA, MUFA, PUFA and trans fat as a percentage of total energy are 33·3, 14·0, 13·6, 5·6 and 0·5 %, respectively. Total fat, SFA and trans fat intakes since 2005 remained largely stable over time with all displaying minor decreases of <1 %. Adherence to SFA recommendations remains inadequate, with only 7 % of the population complying. Insufficient compliance with PUFA (71 %) and EPA and DHA (DHA; 16 %) recommendations was also noted. CONCLUSION: Children in Ireland continue to meet the total fat and trans fat target goals. Adherence to MUFA and PUFA recommendations has also significantly improved. However, deviations for some fats remain, in particular SFA. These findings are useful for the development of dietary strategies to improve compliance with current recommendations.

Dairy Consumption and Metabolic Health.

Milk and dairy foods are naturally rich sources of a wide range of nutrients, and when consumed according to recommended intakes, contribute essential nutrients across all stages of the life cycle. Seminal studies recommendations with respect to intake of saturated fat have been consistent and clear: limit total fat intake to 30% or less of total dietary energy, with a specific recommendation for intake of saturated fat to less than 10% of total dietary energy. However, recent work has re-opened the debate on intake of saturated fat in particular, with suggestions that recommended intakes be considered not at a total fat intake within the diet, but at a food-specific level. A large body of evidence exists examining the impact of dairy consumption on markers of metabolic health, both at a total-dairy-intake level and also at a food-item level, with mixed findings to date. However the evidence suggests that the impact of saturated fat intake on health differs both across food groups and even between foods within the same food group such as dairy. The range of nutrients and bioactive components in milk and dairy foods are found in different levels and are housed within very different food structures. The interaction of the overall food structure and the nutrients describes the concept of the 'food matrix effect' which has been well-documented for dairy foods. Studies show that nutrients from different dairy food sources can have different effects on health and for this reason, they should be considered individually rather than grouped as a single food category in epidemiological research. This narrative review examines the current evidence, mainly from randomised controlled trials and meta-analyses, with respect to dairy, milk, yoghurt and cheese on aspects of metabolic health, and summarises some of the potential mechanisms for these findings.