Trial Search Results

Weight Loss Diet Study: Low Carb vs Low Fat

The traditional weight loss diet recommended by health professionals has been a low-fat, high-carbohydrate, calorie restricted diet. This recommendation has been challenged by a number of alternative dietary strategies, particularly low-carbohydrate diets. In several recent weight loss studies insulin resistant adults had more success with low- vs. high-carbohydrate diets, in contrast to insulin sensitive adults who had either more success or comparable success with the low-fat diets. The investigators enrolled 61 people with a wide range of insulin sensitivity/resistance. After determining their insulin resistance status, the investigators will split them in the middle and randomly assign them to one of four groups for six months: (1) Low-Carbohydrate/Insulin Resistant (LC/IR); (2) Low-Carbohydrate/Insulin Sensitive (LC/IS); (3) Low-Fat/Insulin Resistant (LF/IR); and (4) Low-Fat/Insulin Sensitive (LF/IS) (15 people/group). After 6 months the participants will switch diet for the following 6 months, i.e. those randomized to the Low-Carbohydrate diet will switch to the Low-Fat diet and vice-versa. The primary outcome of this study is to determine whether weight loss success can be increased if one follows the dietary approach appropriately matched to their insulin resistance status. Secondary outcomes include fasting insulin, glucose, lipids, and fatty acid composition.


Stanford is currently not accepting patients for this trial.

Lead Sponsor:

Stanford University

Collaborator: Hass Avocado Board

Stanford Investigator(s):


  • Behavioral: Low-Carbohydrate Diet
  • Behavioral: Low-Fat Diet




Inclusion Criteria:

   - Age: > or = 18 years of age

   - Women: Pre-menopausal (self-report) and <50 years of age

   - Men: <50 years of age

   - Race/Ethnicity: All

   - BMI (body mass index): 28-40 kg/m2 (need to lose >10% body weight to achieve healthy

   - Body weight stable for the last two months, and not actively on a weight loss plan

   - No plans to move from the area over the next 14 months

   - Available and able to participate in the evaluations and intervention for the study

   - Willing to accept random assignment

   - To enhance study generalizability, people on medications not noted below as specific
   exclusions can participate if they have been stable on such medications for at least
   three months

   - Ability and willingness to give written informed consent

   - No known active psychiatric illness

Exclusion Criteria:

   - Pregnant, lactating, within 6 months post-partum, or planning to become pregnant in
   the next 12 months; no menstruation for the previous 12 months

   - Diabetes (type 1 and 2) or history of gestational diabetes or on hypoglycemic
   medications for any other indication

   - Prevalent diseases: Malabsorption, renal or liver disease, active neoplasms, recent
   myocardial infarction, hypertension (except for those stable on hypertensive
   medications) (<6 months) (patient self-report and, if available, review of labs from
   primary care provider)

   - Smokers (because of effect on weight and lipids)

   - History of serious arrhythmias, or cerebrovascular disease

   - Uncontrolled hyper- or hypothyroidism (TSH not within normal limits)

   - Medications: Lipid lowering, diabetes medications, and those known to affect
   weight/energy expenditure

   - Excessive alcohol intake (self-reported, >3 drinks/day)

Ages Eligible for Study

18 Years - 50 Years

Genders Eligible for Study


Not currently accepting new patients for this trial

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Antonella Dewell