A “diet” is simply the sum of all of the food and drink consumed habitually by a person or group of people. Not all diets are healthy. In fact, many diets that could result in weight loss are potentially dangerous. If a diet makes claims that seem “too good to be true,” it probably is. In order for a diet to contribute to health it should incorporate three important characteristics:
1. Effective – The diet should be effective in producing results.
2. Safe – The diet should not have dangerous effects.
3. Sustainable – The diet should be a lifestyle choice that is sustainable.
Our diets are powerful tools that can be used to both maintain and contribute to health, or destroy it. Our lifestyles, and importantly, what we eat, contribute significantly to the prevention or development of serious chronic diseases.
What about other popular diets I have heard about? How can I know if they are good or not?
When you read or hear about a new popular diet, ask yourself, “Is this diet effective, safe, and sustainable?” Many “fad” diets have come and gone as people have realized they are neither safe nor sustainable, even though they may have been effective for weight loss.
For example, the hormone HCG was first introduced as a tool for weight loss in the 1950s. Produced by the placenta during human pregnancy, it was thought that injecting HCG into the blood stream would “reset” the metabolism, with the promise to shed enormous amount of weight very rapidly. A very low calorie diet (fewer than 500 calories per day) was always recommended in conjunction with the injections. As a result of dozens of scientific studies, it was determined that HCG did not significantly contribute to weight loss, and any weight loss achieved was likely a result of the restrictive low calorie diet. The FDA has since stated that HCG diet products are illegal. While this diet may have been effective at producing weight loss results, it certainly was not safe (consuming fewer than 500 calories per day is harmful when not monitored by a physician), or sustainable (dieters may not consume sufficient vitamins, minerals, or proteins, which are all needed to sustain health).
For more information on how to interpret diet-related stories, see “Deciphering Media Stories on Diet” from the Harvard School of Public Health.
Learn how powerful diet can be at influencing health below:
How can I...
Toggle ItemLower my cholesterol?Simultaneously increasing foods that lower LDL (e.g. whole grains, fruit, vegetables, fish, legumes), and restricting foods that increase LDL (e.g. red meat, high-fat dairy, shortening) can help lower cholesterol. It is also important to maintain a healthy weight and engage in regular exercise.
11 Foods That Lower Cholesterol (Harvard Health Publications)
Know Your Fats (American Heart Association)
Fats and Cholesterol(Harvard School of Public Health)
Toggle ItemLose weight, or maintain a healthy weight?While there are many factors that affect weight, consuming fewer calories than you expend is a key component of weight loss. Expending more calories through regular physical activity also contributes to weight loss. Consuming mainly high-quality foods, in addition to considering caloric value, helps promote a healthy weight.
Healthy Weight (Harvard School of Public Health)
Healthy Weight Checklist(Harvard School of Public Health)
Losing Weight (CDC)
Toggle ItemPrevent diabetes, or maintain blood glucose levels as a diabetic?A plant-based diet and regular physical activity can prevent diabetes onset and help manage diabetes. Limiting refined carbohydrates and sugary drinks, and maintaining a healthy weight are important.
Preventing Diabetes (Harvard School of Public Health)
Are You at Risk? (American Diabetes Association)
Choosing What, How Much, and When to Eat (American Diabetes Association)
Toggle ItemLower my blood pressure?Reducing consumption of sodium (salt), increasing intake of potassium, limiting alcohol intake, and following a healthy diet or the DASH diet eating pattern all have been shown to help prevent hypertension (high blood pressure). Weight loss is another significant factor for lowering blood pressure.
Dietary Approaches to Prevent and Treat Hypertension (American Heart Association)
Preventing CVD (Harvard School of Public Health)
Controlling Blood Pressure(CDC)
Following the DASH Eating Plan (NIH/NHLBI)
Toggle ItemEat healthy?There is no “one way” to eat healthy. Balance, variety, nutrition, quantity, and freshness each play a role in a healthy diet, but they may vary from person to person. Plant-based diets have been shown to be the most effective at preventing diseases and maintaining weight. Eating real, minimally-processed food is a good idea. A healthy diet includes vegetables, fruits, whole grains, healthy proteins, and vegetable oils in moderation. Water should be the primary drink.
Healthy Eating (American Heart Association)
Healthy Eating Plate (Harvard School of Public Health)
Healthy Eating for a Healthy Weight (CDC)
Toggle ItemContribute to better athletic performance?It is important to consume sufficient carbohydrate and protein to meet energy and tissue repair requirements, and enough fat to support vitamin retention and weight maintenance. Water is important before, during, and after exercise. Sports drinks help maintain blood glucose and electrolyte levels before, during, and after long, high-intensity exercise.
Nutrition and Athletic Performance (American College of Sports Medicine)
Nutrition and Performance(NCAA)