Observational studies have shown a controversial relationship between dietary fat intake and Alzheimer's disease, and the causal effects are unclear.

To assess the causal effects of total fat, saturated fat and polyunsaturated fat (PUF) intakes on the risk of Alzheimer's disease.

A two-sample Mendelian randomisation analysis was performed using genome-wide association study summary statistics on different types of fat intake from UK Biobank (n = 51 413) and on late-onset Alzheimer's disease (LOAD; 4282 cases, n = 307 112) and all forms of Alzheimer's disease (6281 cases, n = 309 154) from the FinnGen consortium. In addition, a multivariable Mendelian randomisation (MVMR) analysis was conducted to estimate the effects independent of carbohydrate and protein intakes.

Genetically predicted per standard deviation increase in the total fat and saturated fat intakes were associated with 44 and 38% higher risks of LOAD (total fat: odds ratio = 1.44, 95% CI 1.03–2.02; saturated fat: odds ratio = 1.38, 95% CI 1.002–1.90; P = 0.049). The associations remained significant in the MVMR analysis (total fat: odds ratio = 3.31, 95% CI 1.74–6.29; saturated fat: odds ratio = 2.04, 95% CI 1.16–3.59). Total fat and saturated fat intakes were associated with a higher risk of all forms of Alzheimer's disease in the MVMR analysis (total fat: odds ratio = 2.09, 95% CI 1.22–3.57; saturated fat: odds ratio = 1.60, 95% CI 1.01–2.52). The PUF intake was not associated with LOAD or all forms of Alzheimer's disease.

This study indicated that total dietary fat intake, especially saturated fat, contributed to the risk of Alzheimer's disease, and the effects were independent of other nutrients. These findings informed prevention strategies and management for Alzheimer's disease directly towards reducing dietary saturated fat intake.

The purpose of this study was to assess the validity of MEDFICTS (Meats, Eggs, Dairy, Fried foods, fat In baked goods, Convenience foods, fats added at the Table, Snacks) questionnaire in Turkish population.

MEDFICTS questionnaire is a brief dietary assessment tool developed as part of the National Cholesterol Education Program Adult Treatment Panel guidelines, and it measures the adherence to Step 1 and Step 2 diets that are recommended for the prevention and treatment of CVD. MEDFICTS questionnaire was administered with 3-d food record to compare overall dietary fat intake.

This study was conducted at the Hacettepe University (Ankara, Turkey) in 2017.

Subjects were university students, recruited from several departments of Hacettepe University by trained dietitians. A total of 442 adults (249 females and 194 males) between the ages of 18 and 31 years participated in the study. Students with CVD were excluded.

Total fat intake ratio was higher than the recommended level for both males and females (39·4 % and 39·9 %, respectively). Mean MEDCISTS score was 66·3 ± 27·24 points. Total energy, total fat, SFA and cholesterol intakes from 3-d food records within the different MEDFICTS diet groups significantly differed (P < 0·001 for all). Receiver operating characteristics curve analysis demonstrated that a cut-off point of 60 showed 80 % sensitivity and 65 % specificity.

Our data indicate that the MEDFICTS questionnaire is moderately accurate; however, sensitivity analysis did not demonstrate the recommended 40 points as an optimal cut-off point for Turkish population.

To identify the food that has the greatest effect on the variation in the percentage of energy intake derived from fat and saturated fatty acids for the consumption of a Spanish population.

A cross-sectional study of food consumption, using the 24-hour recall method for three non-consecutive days, one of which was a non-working day. Subjects were interviewed by trained interviewers in the subjects' homes. We used multiple linear regression for statistical analysis.

The citizens of Reus.

One thousand and sixty subjects over five years old, randomly selected from the population census of Reus.

In both sexes, the foods that mainly determine a high consumption of fat are oil and red meat while those that determine a lower consumption of fat are bread, savoury cereals and fruit. The foods that mainly determine a high consumption of saturated fatty acids are red meat and whole-fat dairy products while those that determine a low consumption are bread, savoury cereals and fruit.

In our population, feasible variations in the intake of some foods – less than one portion – would reduce the estimated percentage of energy intake derived from fat and saturated fatty acids by a quantity considered important for cardiovascular disease prevention. The periodic identification and quantification of the food that most affects the dietary fat profile will help in drawing up dietary guidelines with more reasonable strategies for consuming a healthier diet and decreasing the risk of developing nutritional disorders.