Eligibility Details:
Inclusion Criteria:
1. All participants will be obese. Obesity will be defined as BMI ≥ 30 kg/m2 at the
baseline study visit. An upper limit of BMI will be set at 49 kg/m2 to include a wide
range of obese men and women with a reasonable probability of losing weight in the
context of a dietary behavioral intervention.
2. Participants must have at least one co-morbid condition that increases risk of
cardiovascular disease (history of CVD, type II diabetes mellitus, fasting plasma
glucose>100 mg/dL, metabolic syndrome as defined by ATP III criteria, hypertension,
hyperlipidemia, WC>40 in among men or >35 in among women).
3. All potential participants must be willing and able to provide informed consent.
Exclusion Criteria:
1. History of any bariatric surgery, including gastric banding, Roux-en-Y and duodenal
switch with biliopancreatic diversion procedures, vertical banded gastroplasty, etc.
2. Currently on a diet or using prescription weight loss medications, and/or experienced
weight loss >15 pounds within 6 months of study entry.
3. Regular use of alcohol >3 beverages per day or 21 beverages per week (1 standard
beverage = 350 mL of 5% alcohol beer, or 150 mL of 12% wine, or 45 mL of 80-proof
distilled spirits), amphetamines, cocaine, heroin, or marijuana over past 6 months.
4. Past or present history of eating disorder (including anorexia, bulimia or binge
eating disorder) or severe/untreated psychiatric illness which may affect
participation in study interventions.
5. Strict dietary concerns (e.g., vegetarian or kosher diet, significant nut or multiple
food allergies). This is an exclusion because participant may not be able to fully
participate in the intervention.
6. For women, current pregnancy or breastfeeding or plans to become pregnant during the
study period. This is an exclusion because weight loss is contraindicated during
pregnancy.
7. Plans to move out of the study area (>1 hour from study site) or difficulty to come to
the study site. This is an exclusion because these conditions may interfere with the
ability to fully participate in and complete the study.
8. Participation of another household member in the study; employees or persons living
with employees of the study. This is an exclusion because randomization of more than
one participant in a household to differing diets may cause conflict within a
household and limit engagement in the intervention. Employees of the study are
excluded due to potential conflicts of interest and knowledge of study assignments.
9. Participation in other lifestyle intervention trials currently. This is an exclusion
because interference with ability to determine whether study interventions are
responsible for outcomes.
10. Medical condition in which a carbohydrate restricted diet may not be advised (eg.
severe renal impairment, osteoporosis, untreated thyroid disease, frequent gout
attacks, Type I diabetes). This is an exclusion because participant may not be able to
fully participate in the intervention.
11. Hospitalization for a CVD event such as myocardial infarction, stroke, TIA, coronary
revascularization, heart failure, peripheral artery disease, or unstable angina within
the last 6 weeks or unstable coronary artery disease. Major new medical illness
including renal disease requiring dialysis, a life-threatening illness with life
expectancy less than six months, or cancer requiring chemotherapy or radiation
treatment in the previous two years. [NOTE: potential participants may still qualify
if they have had treatment for an early stage cancer in the past two years and the
prognosis is excellent.] This is an exclusion because these conditions may interfere
with the ability to fully participate in and complete the study.
12. MMSE score < 23 or dementia. This is an exclusion because it may interfere with the
ability to fully participate in the study.
13. Non-English speaking, a visual impairment or a hearing impairment that interferes with
study participation. This is an exclusion criterion because these potential
participants may not be able to participate fully in the intervention.
14. In addition to the above criteria, investigator discretion will be used to determine
if the trial is unsafe or not a good fit for the potential participant.