Participants will be twenty (n = 20) healthy individuals from the community who are motivated to lose weight. Approximately 60 people will be recruited in order to obtain 20 complete data sets. Participants will be required to be aged 18-50 years, have a body mass index > 27 kg/m2, and have no serious medical condition. Participants will undergo a physical examination ensuring it is safe for them to participate in both the diet and imaging components of the study.

Inclusion Criteria:

Participants must be 18-50 years old, right handed and have a BMI > 27 kg/m². They must be willing to follow either of the two diets.

Exclusion Criteria:

1. weigh over 300lbs.
2. have uncontrolled hypertension (systolic >160mm Hg, diastolic >100mm Hg)
3. have hypotension (systolic <90 mm Hg, diastolic <60 mm Hg)
4. have coronary heart disease, or cardiac rhythm disorder
5. cerebrovascular disease or peripheral vascular disease that requires intensive hyperlipidemic therapy
6. other significant co-morbid illnesses such as liver disease (AST or ALT > 100), kidney disease (serum creatinine > 1.5), cancer, severe emphysema, severe hypertriglyceridemia (TG>500)
7. have diabetes (insulin or diet controlled)
8. have a current psychiatric disease
9. have current alcohol abuse (greater than 12 drinks per week)
10. have current drug abuse (or treatment within the last year)
11. use of psychiatric medications (including antidepressants, anti-anxiety agents, anti-psychotics, "muscle relaxants" or any other drug that influences mood, cognition, or neurotransmitter systems, i.e. dopamine, norepinephrine, acetylcholine, serotonin, GABA, and glutamate)
12. have had or have an eating disorder including anorexia nervosa, bulimia nervosa, eating disorder not otherwise specified, binge eating disorder, or any other form of disordered eating
13. have had any bariatric/weight loss surgery
14. be taking any diet pills (prescription or over the counter)
15. have been on any diet in the last 3 months
16. have any restrictive dietary requirements (including: vegetarians, vegans, or any other dietary restraints)
17. have any food allergies
18. be on an exclusively ethnic diet
19. be females who are pregnant, nursing mothers or likely to become pregnant
20. have any major medical condition that would make participation unsafe (e.g., have pacemaker or other metallic implant (including dental, orthopedic, or IUD), uncomfortable (e.g., chronic pain), confound results (e.g., psychiatric condition)
21. be left handed
22. have glaucoma, color blindness
23. be using experimental or investigational drugs
24. or suffering from claustrophobia