The 26-year-old "Mean Girls" and "Freaky Friday" actress has been "extremely emotional this past week and is finding comfort in food," a source told the celebrity news website Thursday.
"Lindsay can't stop eating, and has gained five pounds because she has such poor eating habits," the insider said. "She has been exercising, but she just doesn't have a lot of energy because she is no longer taking Adderall, which is a psychostimulant medication that contains amphetamine. She has been talking to a nutritionist at Betty Ford about eating healthier."
Lohan checked into Betty Ford May 2 as part of a 90-day sentence for reckless driving. Lohan pleaded no contest to the charge in March and agreed to enter rehab, spend 18 months in psychotherapy and serve 30 days of community service.
The actress has argued she needs Adderall because she has attention deficit disorder, however, Betty Ford doctors deemed her prescription unnecessary and are keeping her from taking the medication while she undergoes treatment at the facility for drug and alcohol addiction.