Safe and healthy weight loss is becoming increasingly important as the obesity burden in Canada continues to grow, with 63.1% of adult Canadians classified as overweight or obese in 2018 according to Statistics Canada. Ketogenic diets are diets that are low in sugar and are very popular for weight loss. However, these diets may be associated with adverse long-term cardiovascular health outcomes depending on the source of protein supplementation (animal versus plant-based). We do not know why this is the case. The objective of this study is to investigate how fat and inflammation are affected during a plant- or animal-based ketogenic diet weight loss intervention. We will measure how much weight is lost, what happens to body fat and blood risk factors when participants lose weight with a ketogenic diet that has plant or animal-based proteins. This study will allow us to examine the effect of protein source on health risk factors in the context of a ketogenic diet. Doing so will enable NFH to design of better protein supplements to support better health and well-being.