What has the most calories per ounce?
                                
                                
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                                    4 min read                                
                            
                                According to the American Heart Association, dietary fats contain 9 calories per gram—more than twice the 4 calories per gram found in protein and carbohydrates. This fundamental fact of nutrition means that, by weight, pure oils and fats are the most calorie-dense substances you can consume. The specific food with the highest calorie density will therefore be a type of fat or oil.