Nutrition is a major factor influencing obesity associated heart disease risk, however many people with this disease do not follow nutritional recommendations. This review of 155 studies aimed to summarise dietary aspects of heart disease prevention. The paper began by outlining the role of obesity through the development of other disorders that contribute to heart disease, such as type 2 diabetes, high blood pressure and blood sugar imbalance. The quantity and distribution of fat tissue also can contribute to heart disease risk, especially if it is located within the heart or around the major organs of the body. Dietary factors which can increase heart disease risk were described as an increased intake of processed foods, sugar, salt and certain fats and low intakes of fruit, vegetables, fibre, whole grains, beans and nuts. The Mediterranean diet, the dietary approaches to stop hypertension (DASH) diet, plant-based diets, the portfolio dietary pattern and low carbohydrate diets were all reviewed and although mixed results were stated for low carbohydrate diets, most of the diets reviewed reported improved heart disease outcomes. The role of intestinal microbiota in heart disease were also reviewed and the influence of a poor diet was implicated in imbalanced gut microbiota and the development of heart disease. It was concluded that an unhealthy diet can contribute to heart disease and that dietary patterns such as the Mediterranean diet and plant-based diets may be favourable for its management. This study could be used by healthcare professionals to individualise dietary recommendations for patients with heart disease or who are at risk of it.