This phase 1 study tests whether use of the Modified Atkins Diet (MAD) can improve motor impairment after stroke. It is based on the hypothesis that after stroke, the brain's utilization of glucose, it's primary source of energy, is disrupted. The MAD is a low-carbohydrate diet that has can switch the body's metabolism from using glucose to using products of fat metabolism, so-called ketones. Ketones may act as an alternative energy substrate for the brain. Ketones also have several neuroprotective effects after stroke.

Inclusion Criteria:

• Age 18-99
• First time unilateral hemispheric ischemic stroke. Not more than 12 weeks after acute stroke.
• Burke Stroke Rehabilitation Unit Inpatient.
• Preserved cognitive ability to understand commands and participate in outcome measures and to give informed consent. In patients with aphasia, cognitive ability to give consent will be determined by a physician.
• Upper extremity motor impairment with an UE Fugl Meyer score ≤ 56/66
• Independence in ADLS/ absence of major impairment prior to stroke

Exclusion Criteria:

• Hemorrhagic stroke
• Uncontrolled hyperlipidemia with LDL > 250 on admission
• Uncontrolled Diabetes mellitus with BS > 300 averaged over the first day of admission
• Nutritional risk as defined by BMI < 18.5 or by a score of 2 or higher on the Malnutrition Universal Screening Tool (scores BMI, % of unplanned weight loss in last 3-6 months and question whether patient is acutely ill)
• Decreased renal function with eGFR <30%
• Stage III and IV pressure ulcers
• Osteoporosis not sufficiently treated with oral Calcium and Vitamin D supplements
• CHF as defined by class III or worse
• Hypersensitivity/allergy to cholesterol lowering medications
• H/o kidney stones within last 1 year prior to stroke or medications predisposing to kidney stones such as Topamax, carboanhydrase inhibitors
• Inability to tolerate an oral diet and need for tube feeds
• Active enrollment in any other interventional studies at Burke; enrollment in observational studies or studies using TMS as a measurement may not pose exclusion criteria
• Cognitively unable to follow instructions.

Individual Participant Data will not be disclosed.