Impact of Reducing Dietary Intake of Red and Processed Meat Intake on Fasting Lipemia in Healthy Participants
Condition: Lipidemia
MeSH terms: Hyperlipidemias
Study type: Interventional

Summary: 
      Excessive meat consumption, particularly of red and processed meat, is associated with
      increased risk of developing a range of chronic diseases. Meat production also significantly
      contributes to the production of global greenhouse gasses (GHG). Given the predicted global
      increase in the human population, coupled with the rise in demand for meat within emerging
      economies, it has been suggested that strategies to alter dietary patterns and reduce meat
      intake should be devised. With the provision of appropriate non- or reduced-meat
      alternatives, this study aims to investigate whether free living subjects can significantly
      reduce their meat intake, and whether such dietary changes positively impact on a range of
      health measures
    

Detailed description: 
      In UK adults, meat provides approximately 40% of the average daily protein intake and makes a
      significant contribution to intake of thiamin, niacin, vitamin B12, iron, zinc, potassium,
      and phosphorus. However, excessive consumption, particularly of red and processed meat, is
      associated with increased risk of developing a range of chronic diseases, including
      cardiovascular disease (CVD), obesity, type 2 diabetes and some cancers. Meat production
      significantly contributes to the production of greenhouse gasses (GHG) and hence global
      warming. Given the predicted global increase in the human population, coupled with the rise
      in demand for meat within emerging economies, it has been suggested that concerted efforts
      should be made to alter dietary patterns and reduce meat intake. Moreover, a number of
      reports have suggested that replacing meat with non-meat protein-rich products has health
      benefits. Such products tend to be inherently lower in total and saturated fat and, higher in
      fibre and as such, could also be cardioprotective.

      The aim of this trial will be to investigate whether, with appropriate non/reduced-meat
      alternatives and motivational support, free living subjects can significantly reduce their
      meat intake and whether such dietary changes positively impact on a range of cardiovascular
      risk factors.

      Trial design; A non-randomised, single group study design, with an initial control period
      will be used.

      Participants; Forty healthy men and women will be recruited from the general population of
      Nottinghamshire, UK. All participants will attend the David Greenfield Human Physiology Unit
      (Queen's Medical Centre, Nottingham, UK) for an initial medical screening visit to confirm
      health status. In addition, blood pressure (BP) will be measured at the left upper arm (after
      lying semi-supine for 5min) using automated oscillometry, and body mass index (BMI) will be
      calculated from measured height and weight. If participants are suitable to take part with
      regards to their health questionnaire and BMI measures, a venous blood sample will then be
      taken to assess full blood count, urea, and electrolytes. Those taking lipid-lowering
      medication, or who report using nutritional strategies to lower their cholesterol, will be
      excluded. Participants will be accepted onto the trial if they report habitual consumption of
      4-5 portions of red and/or processed meat per week (with 3-4 of these being consumed as main
      meals), they do not have food allergies related to soya or mycoprotein, and do not
      demonstrate any clinically significant abnormalities on screening.

      Study Protocol; After recruitment, participants will be asked to record all food intake
      (including snacks and drinks) in a diet diary, for 4 days (3x week or work days, and 1x
      weekend or rest day) prior to assessment visit 1, for baseline assessment of macronutrient
      and energy intake. Individuals will be asked to complete further 4-day diet diaries in the
      week before assessment visits 2,3 and 4 (weeks 4, 10, and 16), to assess any changes in
      macronutrient or energy intake and meat consumption which may have occurred as a consequence
      of the intervention. Household measures will be used to estimate portion size, and diaries
      will be analysed using a food composition database. To calculate habitual diet composition, a
      mean daily intake will obtained from all 4 days of each recording period, and these data will
      be combined to produce group means.

      Assessment visits will take place in the morning after the individual has fasted from
      midnight the night before. Initially, measurement of body mass will be made to the nearest
      0.1kg using a Seca 882 Digital Scale, and waist and hip circumference will be assessed (with
      the participant standing) mid-way between the lowest rib and the iliac crest, and at the
      greater trochanters, respectively. Participants will then be asked to rest, semi-supine, on a
      couch for >5min before having their resting BP measured, and estimation of body composition
      made using bioelectrical impedance. A 5ml fasting blood sample will be taken for
      determination of serum insulin, total cholesterol, high density lipoprotein cholesterol
      (HDL), low density lipoprotein cholesterol (LDL), triacyl glycerides (TAG) and whole blood
      glucose. In a subset of the cohort (n=26, 13 Male:13 Female), flow mediated dilatation (FMD)
      will also be measured on the laboratory visits when fasted, after resting semi-supine for 1
      and 2 hours.

      Intervention; After visit 1 (week 0) assessment, participants will be asked not to make any
      changes to their lifestyle and to continue their habitual diet until visit 2 (week 4) when a
      second assessment will be made ('control' period). The 12 week 'intervention' period will
      begin on the day after the second study visit. Participants will be given information
      regarding how meat intake can safely be reduced in their diet, including a recipe book
      containing ideas for meals using meat analogues and other protein sources. A range of frozen
      meat-free (soya or mycoprotein 'mince', mycoprotein sausages, meatballs and 'steak strips')
      and reduced meat products (pork sausages, beef meatballs, beef mince and beef burgers made
      with 50% meat and 50% soya or mycoprotein) are available for the participants to use to aid
      this reduction in red meat intake. In addition, a range of dried beans (red kidney, haricot,
      black turtle), pulses (chick peas, green and red lentils) and grains (quinoa) will also be
      offered. Weekly telephone contact with the study participants will be maintained over the
      intervention period to improve compliance, to identify any problems and to arrange further
      food deliveries.
    

Intervention name(s): Meat reduction
Intervention type(s): Behavioral
Intervention description(s): Advice, Motivational material and food products provided to participants
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: meat intake; meat analogues; LDL Cholesterol; HDL Cholesterol