MNT: Disorders of Lipid Metabolism (2015)


van de Laar FA, van de Lisdonk EH, Lucassen PL, Tigchelaar JM, Meyboom S, Mulder J, van den Hoogen JM, Rutten GE, van Weel, C. Fat intake in patients newly diagnosed with type 2 diabets: A four-year follow-up study in general practice. Br J Gen Prac. 2001; 54: 177-182.

PubMed ID: 15006122
Study Design:
Prospective Cohort Study
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  • To evaluate the fat consumption of patients with newly diagnosed type II diabetes in Dutch general practice compared with reference values for the general population
  • To evaluate alterations in fat consumption eight weeks after the initial diagnosis and referral to a dietitian according to the Dutch guidelines for treatment of type II diabetes
  • To determine the fat consumption after four years of follow-up compared with initial consumption in these patients.
Inclusion Criteria:
  • Followed by one of 46 general practitioners working in 33 general practices throughout the Netherlands
  • Newly diagnosed type II diabetes: Defined according to criteria established by the World Health Organization, including:
    • Symptoms suggestive of diabetes mellitus and a fasting blood glucose 6.7mmol per L or more and 20mmol per L
    • Asymptomatic newly diagnosed diabetes with fasting blood glucose higher than 6.7mmol per L on two or more occasions.
  • Aged 40 years to 70 years
  • Informed consent.
Exclusion Criteria:
  • Not meeting WHO criteria for newly diagnosed diabetes mellitus
  • Less than 40 years or more than 70 years of age.
Description of Study Protocol:


Recruited from 33 general practices throughout the Netherlands.


  • All patients were referred to a registered dietitian. Dietary intervention consisted of two consultation sessions with a four-week period in which patients received dietary advice concerning all aspects of medical nutrition therapy for diabetes, tailored to their individual needs. Dietitians were informed about baseline fat consumption in all patients but otherwise did not receive extra training or use of special protocols. Patients who still had fasting blood glucose 6.7mmol per L or more after eight weeks were eligible for oral anti-diabetic therapy. These patients were asked to participate in a 30-week randomized controlled trial comparing acarbose with tolbutamide.
  • Measurements took place at diagnosis, after eight weeks and four years, and included dietary consumption evaluated with the use of a 104-item food frequency questionnaire, body weight and height, medical history, comorbidity, medication use, additional visits with dietitian or other sources of dietary information, serum glycosylated hemoglobin, serum lipids and serum glucose levels.


Dietary intervention by registered dietitian.

Statistical Analysis

  • Results given as mean ± standard deviation
  • Student's two-sample T-tests performed for comparison between groups
  • Student's one-sample test used for comparison of results between subsequent measurements
  • Repeated measure analysis performed to assess an overall time effect
  • T-test P<0.0024 and for repeated measure analysis P<0.0072 was considered significant.


Data Collection Summary:

Timing of Measurements

  • All measurements were taken at diagnosis, after eight weeks and after four years:
    • Consumption of dietary fat measured with a 104-item food frequency questionnaire in which the past month was used as the reference period
    • Values for total energy, total fat, saturated fatty acids, monounsaturated fatty acids and cholesterol were calculated using a computer program and results from questionnaire
    • Body weight and height without shoes and with light clothing
    • Data on medical history, co-morbidity and the use of medications obtained from patients' records by their general practitioner
    • Information regarding any additional visits to a dietitian or use of other sources for dietary information was recorded with the help of short questionnaire
    • Glycosylated hemoglobin, glucose and lipids.
  • At the four-year follow-up, GPs provided information about the use of anti-diabetic and cholesterol-lowering medication during the interval.

Dependent Variables

  • Dietary fat consumption
  • Total energy, total fat, saturated fatty acids, monounsaturated fatty acids and cholesterol intake.
Independent Variables

Dietary intervention consisting of two consultation sessions within a four-week period.

Control Variables

  • Gender
  • Age
  • Body weight and height
  • Medical history, co-morbidity and use of medications obtained from patients' records by their general practitioner
  • Visits to dietitian or use of other sources for dietary information recorded with help of short questionnaire
  • Glycosylated hemoglobin, glucose and lipids
  • Blood pressure.


Description of Actual Data Sample:
  • Initial N: A total of 144 subjects (69 males, 75 females)
  • Attrition (final N): 106 subjects
  • Age: 57.8±8.3 years
  • Other relevant demographics: Baseline results for patients who did not participate in the eight-week or four-year evaluation did not differ significantly from results of patients whose measurements were not missing
  • Anthropometrics: BMI of 29.5±5.2kg/m2
  • Location: Netherlands.


Summary of Results:

Key Findings

Fat consumption:

  • Compared with reference figures for the general population, patients had a higher intake of energy and higher fat consumption
  • At eight-week follow-up, there was a decrease in total energy intake, total fat, saturated fatty acids and monounsaturated fatty acids, while polyunsaturated fatty acids and relative cholesterol intake did not change
  • At four-year follow-up, consumption of total fat and monounsaturated fatty acids increased significantly compared to eight weeks but remained significantly lower than baseline
  • Repeated measure analysts showed similar results, with the exception that the difference in consumption of total fat between eight weeks and four years was not significant
  • Male and female patients showed similar fat consumption at baseline except for energy and cholesterol intake, which were higher in males
  • Women showed a more profound decrease in consumption of total fat, monounsaturated fatty acids and saturated fatty acids in both eight-week and four-year measurements
  • The percentage of patients that met guideline regarding saturated fatty acids increased from 7.6% at baseline to 27.4% at the four-year measurement and the percentage of patients consuming less than 7% of energy intake from saturated fatty acids increased from 0.7% to 9.4%.
Variables Change in Mean Difference Diagnosis to Eight Weeks:
Mean (95% CI)
Change in Mean Difference Diagnosis to Four Years:
Mean (95% CI)
Change in Mean Difference Eight Weeks to Four Years:
Mean (95% CI)
Energy intake (MJ per day) -2.2 (-2.6 to -1.7)
-1.8 (-2.3 to -1.2)
0.5 (0.09  to 0.9)
Not significant
Total fat (percentage energy intake) -5.1 (-6.6 to -3.5)
-3.0 (-4.8 to -1.2)
2.5 (1.1 to -3.9)
Saturated fatty acids (percentage energy intake) -2.4 (-3.0 to -1.8)
-3.1 (-3.8 to -2.3)
-0.5 (-1.1  to 0.1)
Not significant
Monounsaturated fatty acids (percentage energy intake) -2.5 (-3.1 to -1.8)
-1.5 (-2.3 to -0.6)
1.0 (0.4 to -1.6)
Polyunsaturated fatty acids (percentage energy intake) 0.3 (-0.4 to -0.9)
Not significant
0.9 (0  to 1.7)
Not significant
0.9 (0  to 1.8)
Not significant
Cholesterol intake (mg per day) -63.1 (-77.8 to -48.3)
-99.7 (-120 to -79.4)
-33.6 (-48.3 to -18.8)
Cholesterol intake (mg per MJ) -0.3 (-1.5 to -1.0)
Not significant
-6.2 (-7.8 to -4.6)
-5.6 (-7.2 to -4.0)

Other Findings

People with BMI higher than 30kg/m2 reported the lowest energy intake.

Plasma Lipids, Glycemic Control and Body Weight
  • After eight weeks and two visits with a dietitian, 25.7% of patients had a fasting blood glucose less than 6.7mmol per L and hemoglobin A1C decreased from 9.0% to 7.8%. All plasma lipid values except for HDL cholesterol and triglycerides improved at eight weeks
  • After four years, hemoglobin A1C and plasma lipids had significantly improved compared with baseline and, except for triglycerides, to the eight-week measurement
  • BMI decreased at the eight-week measurement (P<0.01) but was back at baseline at the four-year measurement.
Diabetes Treatment
  • At the four-year measurement, 18% of patients were still being treated with lifestyle modifications alone
  • Use of cholesterol-lowering medications increased from 7% at baseline to 32% at the four-year follow-up
  • After the first two visits with the dietitian, patients visited the dietitian 0.6±0.9 times per year
  • A total of 77% of patients visited a dietitian less than once a year, 13% between one and two times a year and 10% had two or more consults a year.
Author Conclusion:
Patients in general practice with type II diabetes had an unfavorable fat intake at time of diabetes diagnosis compared with reference values. Shortly after the first dietary consultation, fat consumption decreased to levels similar to general population. After four years, consumption of total fat increased but was still lower than baseline value, with increase due to higher intake of both polyunsaturated fatty acids and monounsaturated fatty acids. Cholesterol intake decreased at eight week and decreased further at four years.
Funding Source:
Dutch Dairy Foundation for Nutrition and Health, Bayer
Reviewer Comments:
  • Authors provided a participant flow diagram to illustrate attrition
  • No control group.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes