Effect of a Low-carbohydrate, High-protein Energy-restricted Diet on Weight and Body Composition Using DXA
Condition: Weight Loss; Body Composition
MeSH terms: Body Weight; Weight Loss
Study type: Interventional

Summary: 
      People often choose certain diets to lose weight or to change their habits or lifestyle. The
      Dukan diet was created in the '70s and took on importance in the last decade. It is a 4 phase
      diet similar to the Atkins diet. However, this diet is aggressive in its first phase because
      it suppresses carbohydrates, the main source of external energy being saturated low-fat
      protein. Studies of this diet are scarce and have been limited to describing the contribution
      of micronutrients. In nutritional practice, it is often assumed that a popular high-protein
      or low-calorie ketogenic diet could cause rapid or unfavourable changes in a patient's weight
      and body composition. However, the effect of these diets in the short or long term on weight
      and on body fat, muscle mass and other components is not clear. This means that body
      composition has not been the main objective when analyzing the effect of a popular diet. For
      this reason, the meta-analyzes focus on weight change and the absence of body composition
      data is a limitation of the selected studies. Changes in body composition due to a popular
      diet should be evaluated with techniques such as DXA. The aim of this study is to analyze the
      effect of a low-carbohydrate, high-protein diet with energy restriction on weight and body
      composition using DXA. For this, a randomized controlled study will be used where a group
      will receive the diet protocol. The control group will have a normal diet, and only one
      oatmeal drink will be added (55 g of oats in 250 ml of water). The drink will contain 1.6 g
      of BetaG per serving according to FDA recommendations that correspond to the 50% BetaG
      required per day.
    

Detailed description: 
      The patients (n = 60) are invited through posters and social networks to recruit a group of
      40 overweight subjects (20% above their ideal weight). The protocol is explained in detail to
      each one, and the patient and two witnesses sign the informed consent. Subjects are assigned
      to one of two groups: group A: high protein diet (HPD) and group B: non-high protein diet
      (NHPD). The NHPD is designed according to Mexican nutrition guidelines according to sex and
      age.

      The main anthropometric and biochemical measurements and diet monitoring are performed in the
      body composition laboratory of the Faculty of Sports Organization (FOD). Four technicians
      (nutritionists) are in charge of taking the measurements and recording the data. The
      principal investigators review the quality of the information and the correct completion of
      the records. Each file will be assigned an identification number. Other nutritionists
      (graduate students) will be in charge of auditing the information according to the protocol
      guidelines. Principal Investigators will resolve any discrepancies between technicians and
      graduate students to ensure data recording, deletion, or reevaluation.

      Each patient is asked for a prior medical examination before entering the study. The data
      from the external medical practitioner are compared with those provided by the patient for
      the present study.

      The main anthropometric variables are measured with the international ISAK methodology. The
      DXA equipment is calibrated daily, and the result is analyzed and analyzed by a researcher
      who evaluates whether the measurement is reliable.

      The data is recorded in printed formats that are immediately scanned to maintain readability.
      Later, they are recorded in an Excel sheet with the patient's identification number. In each
      measurement session, the database is analyzed for abnormal, extreme or unlikely data. Two
      independent researchers are responsible for reviewing the database every day.

      Each patient is cared for by a nutrition student who accompanies him in the basic needs,
      clothing and transfers to the measurement equipment. At the end of the evaluation, patients
      receive a complimentary meal and free transportation home.

      Patients are monitored through WhatsApp to verify the presence of adverse events with the
      diet. Also, for any questions with the procedures. All procedures are recorded in paper and
      electronic form. In addition, they are given an additional number in case of medical
      emergency or consultation with a nutritionist.

      The sample size will be limited in the first stage to 30 patients. Measurements and
      preliminary analysis will be obtained at 0, day four and day fifteen. The last two
      measurements will be taken on day 42 and until the subjects reach their ideal body weight.

      In the case of missing data or defective quality record, subjects will be removed.

      Regarding the statistical analysis, multiple linear regression will be used, where the groups
      and measurements will be compared on the different measurement days. As covariates,
      covariates will be incorporated as initial values, age, sex, BMI, among others, will be
      adjusted. Descriptive statistics will be added.
    

Intervention name(s): High Protein Diet Group; No High Protein Diet Group
Intervention type(s): Other; Other
Intervention description(s): The high protein diet (HPD) group is instructed to follow a low carbohydrate, high protein ketogenic diet. This diet has 4 phases, two of weight loss until reaching the ideal weight (attack and cruise) and two of maintenance (consolidation and stabilization). During the first 2 phases, it allows 100 foods (28 vegetables). The first phase lasts 3-10 days and 72 high-protein, low-fat foods are allowed. In the second phase, there are alternate days between consuming the low glycemic index vegetables plus protein and the next day with just protein. The first two phases are ad libitum. Phase 3 (consolidation) aims to avoid rebound and begins the introduction of complex carbohydrates and legumes in individual servings. In phase 4 (stabilization), the subject returns to a free diet. However, three basic rules are introduced: protein one day a week, the exercise of at least 20 min/day (optional) and consumption of 3 tablespoons of oat bran/day.; No high protein diet (NHPD) group received an oat beverage consisted of 55 g of oats in 250 ml of water. Beverage contained 1.6 g of betaG per portion according to FDA recommendations corresponding to 50 % of betaG required per day. Weekly bags containing oat mixture were provided on day 0 and in the third week of the trial. No additional instructions about diet, exercise program or pharmacological treatment was implemented.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This is a randomized controlled clinical study. Subjects are assigned to one of two groups: the intervention group (group A or high protein diet or HPD) and the group without high protein diet or NHPD. The assignment is done with the use of MedCalc software and the option to create random groups. Both groups are treated equally except for the procedure or diet. The blind or double-blind procedure is not used in this study. Both groups are treated during the same study period. The maximum number of patients to be evaluated per day will be three. Patients are not mixed from one group or another in each evaluation.
Masking: None (Open Label)
Primary purpose: Treatment