The Role of Phosphorus in Diet Induced Thermogenesis (DIT) of Both Lean and Obese Subjects
Condition: Obesity
Study type: Interventional

Summary: 
      The study aim at:

      Investigating the impact of phosphorus ingestion on DIT of lean and obese subjects consuming
      high carbohydrate meal.

      Investigating the impact of phosphorus ingestion on DIT of lean and obese subjects consuming
      high protein-low phosphorus meal.
    

Detailed description: 
      Subject will be advice to take a weight maintenance diet which contains at least 250-300g of
      carbohydrate per day for the 3 days before each study day and also he/she will be asked to
      avoid any intense physical activity during the day before the day of the test. Overnight
      fasted subjects (> 8 hours) will be requested to attend the testing room at around 8:00 am.
      The he investigators will take the anthropometric measurements (weight, height, waist
      circumference) and determine blood glucose.

      A crossover design study will be used in which each subject will undertake 2 or 3 sessions in
      a random order over 2 or 3 different days which are separated by a minimum of one week. The
      difference between the sessions is the ingestion of placebo ( 4 tablets) or phosphorus (4
      tablets, each contain 125mgof phosphorus) tablets with the appropriate meal.

      Specific Aim 1: The impact of phosphorus ingestion on DIT of lean and obese subjects
      consuming high carbohydrate meal (Table 1: Meal 1).

      This will be divided into two experiments:

      Experiment 1.1: The impact of phosphorus ingestion on DIT of lean subjects consuming high
      carbohydrate meal (16 subjects).

      In this experiment, overnight fasted lean subjects (> 8 hours) will be requested to attend
      the testing room at around 8:00 am. Anthropometric measurements (weight, height, waist
      circumference) will be taken, rest for 30 min, measure resting energy expenditure (REE) for
      30 min, ingest meal with the appropriate supplement and measure postprandial energy
      expenditure (PEE) for 4 hours (see figure 3). In this experiment, subject will undertake 3
      sessions in a random order over 3 different days which are separated by a minimum of one
      week.

      Session 1: Ingestion of phosphorus tablets (4 tablets) alone. No meal. Needed to determine
      the impact of phosphorus alone on DIT Session 2: Ingestion of phosphorus tablets (4 tablets)
      with the high carbohydrate meal (table1: Meal 1).

      Session 3: Ingestion of placebo tablets (4 tablets) with the high carbohydrate meal (table 1:
      Meal 1).

      Experiment 1.2: The impact of phosphorus ingestion on DIT of lean subjects consuming high
      carbohydrate meal (16 subjects).

      In this experiment, overnight fasted obese subjects (> 8 hours) will be requested to attend
      the testing room at around 8:00 am. Anthropometric measurements (weight, height, waist
      circumference) will be taken, rest for 30 min, measure resting REE for 30 min, ingest meal
      with the appropriate supplement and measure PEE for 4 hours (see figure 3). In this
      experiment, subject will undertake 3 sessions in a random order over 3 different days which
      are separated by a minimum of one week.

      Session 1: Ingestion of phosphorus tablets (4 tables) alone. No meal. Needed to determine the
      impact of phosphorus alone on DIT Session 2: Ingestion of phosphorus tablets (4 tables) with
      the high carbohydrate meal (Table 1:Meal 1).

      Session 3: Ingestion of placebo tablets (4 tables) with the high carbohydrate meal (Table
      1:Meal 1).

      Specific Aim 2: The impact of phosphorus ingestion on DIT of lean and obese subjects
      consuming high protein-low phosphorus meal (table 1: Meal 2).

      This will be divided into two experiments:

      Experiment 2.1: The impact of phosphorus ingestion on DIT of lean and obese subjects
      consuming high protein-low phosphorus meal (16 subjects).

      In this experiment, overnight fasted lean subjects (> 8 hours) will be requested to attend
      the testing room at around 8:00 am. Anthropometric measurements (weight, height, waist
      circumference) will be taken, rest for 30 min, measure REE for 30 min, ingest meal with the
      appropriate supplement and measure PEE for 4 hours (see figure 3). In this experiment,
      subject will undertake 2 sessions in a random order over 2 different days which are separated
      by a minimum of one week.

      Session 1: Ingestion of phosphorus tablets (4 tablets) with the high protein meal (table1:
      Meal 2).

      Session 2: Ingestion of placebo tablets (4 tablets) with the high protein meal (table 1: Meal
      2).

      Experiment 2.2: The impact of phosphorus ingestion on DIT of lean and obese subjects
      consuming high protein-low phosphorus meal (16 subjects).

      In this experiment, overnight fasted obese subjects (> 8 hours) will be requested to attend
      the testing room at around 8:00 am. Anthropometric measurements (weight, height, waist
      circumference) will be taken, rest for 30 min, measure REE for 30 min, ingest meal with the
      appropriate supplement and measure PEE for 4 hours (see figure 3). Urine sample over the
      experimental period will be collected. In this experiment, subject will undertake 2 sessions
      in a random order over 2 different days which are separated by a minimum of one week.

      Session 1: Ingestion of phosphorus tablets (4 tablets) with the high protein meal (table1:
      Meal 2).

      Session 2: Ingestion of placebo tablets (4 tablets) with the high protein meal (table 1: Meal
      2).
    

Intervention name(s): Effect of phosphorus
Intervention type(s): Dietary Supplement
Intervention description(s): Ingestion of 500mg of phosphorus ( 4 tablets, each of 125 mg of phosphorus)
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: phosphorus; lean; obese; energy expenditure