Clinical Trial: The Impact Of An Intermittent Energy Restricted Diet On Insulin Sensitivity In Men and Women With Central Obesity

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Randomised Controlled Trial Assessing The Impact Of An Intermittent Energy Restricted Diet On Weight Loss, Insulin Sensitivity and Heart Rate Variability In Men and Women With

Brief Summary: An intermittent energy restricted (IER) diet may modify cardio-metabolic disease risk factors compared to an energy-matched continuous energy restricted (CER) diet. A randomised controlled parallel design trial will determine the impact of a short-term IER diet (2 consecutive days of very low calorie diet (VLCD), 5 days moderate energy restriction each week for a 4 week period), compared to a CER diet, on insulin sensitivity in healthy (disease-free) subjects with central obesity.

Detailed Summary:

Prediabetes rates in England have showed a marked increase, more than tripling between 2003 and 2011. It is characterised by an impaired fasting glucose or impaired glucose tolerance that increases the risk of progression to type 2 diabetes (T2D). It has been estimated that approximately 90% of T2D is attributed to excess weight. Central obesity is a primary driver of increased cardiometabolic risk due to its lipotoxicity effects, promoting a proinflammatory state that facilitates insulin resistance and beta cell dysfunction. A high waist circumference measurement, indicative of central obesity, is associated with increased risk of cardiovascular diseases and T2D, and is a stronger predictor of T2D than BMI. BMI has limitations as an indicator of adiposity since it doesn't distinguish lean from fat mass, and does not indicate body fat distribution. Conventionally, continuous energy restriction (CER) diets have been used for weight loss, which consist of a constant daily energy deficit relative to total energy expenditure. The impact on weight loss and health of an intermittent energy restriction (IER) approach has only rarely been investigated (although the "5:2 diet" has been popularised in lifestyle books aimed at the general public). An IER diet consists of a predefined period of time severely restricting energy intake, alternated with a period of greater energy intake. This approach was shown to confer metabolic benefits in overweight and obese women at risk of breast cancer with baseline BMI of 2445 (Harvie et al., 2013; Harvie et al., 2011).

Rationale: An IER diet using meal replacements (VLCD foodpacks used as total dietary replacements for 2 consecutive days each week, and a food-based energy-restricted diet for the other 5 days of the week) may modify cardio-metabolic disease risk factors compared to an energy-matched CER diet.

  • Revised QUICKI (RQUICKI) [ Time Frame: Baseline ]
    Marker of insulin sensitivity
  • RQUICKI [ Time Frame: day 29 ]
    Marker of insulin sensitivity
  • RQUICKI [ Time Frame: day 31 ]
    Marker of insulin sensitivity


    • Original Primary Outcome: Same as current

    Current Secondary Outcome:

    • Plasma glucose concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma glucose concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma glucose concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma insulin concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma insulin concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma insulin concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma non-esterified fatty acid concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma non-esterified fatty acid concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma non-esterified fatty acid concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma total cholesterol concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma total cholesterol concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma total cholesterol concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma low density lipoprotein (LDL) cholesterol concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma LDL cholesterol concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma LDL cholesterol concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma high density lipoprotein (HDL) cholesterol concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma HDL cholesterol concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma HDL cholesterol concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma triglyceride concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma triglyceride concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma triglyceride concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma total cholesterol:HDL cholesterol ratio [ Time Frame: Baseline ]
      Fasting
    • Plasma total cholesterol:HDL cholesterol ratio [ Time Frame: day 29 ]
      Fasting
    • Plasma total cholesterol:HDL cholesterol ratio [ Time Frame: day 31 ]
      Fasting
    • Homeostasis model assessment estimated insulin resistance (HOMA-IR) [ Time Frame: Baseline ]
      Fasting (calculated from insulin and glucose)
    • Homeostasis model assessment estimated insulin resistance (HOMA-IR) [ Time Frame: day 29 ]
      Fasting (calculated from insulin and glucose)
    • Homeostasis model assessment estimated insulin resistance (HOMA-IR) [ Time Frame: day 31 ]
      Fasting (calculated from insulin and glucose)
    • Plasma adiponectin concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma adiponectin concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma adiponectin concentration [ Time Frame: day 31 ]
      Fasting
    • Plasma leptin concentration [ Time Frame: Baseline ]
      Fasting
    • Plasma leptin concentration [ Time Frame: day 29 ]
      Fasting
    • Plasma leptin concentration [ Time Frame: day 31 ]
      Fasting
    • Same as current

      Information By: King's College London

      Dates:
      Date Received: January 22, 2016
      Date Started: February 2016
      Date Completion:
      Last Updated: July 4, 2016
      Last Verified: July 2016