Ask The Doctors: July 2018
I have multiple risk factors for cardiovascular disease and would like to start a diet that will reduce my risk of heart attack and help me lose weight. What do you suggest?
The Mediterranean diet is one of the healthiest diets for preventing cardiovascular disease, but a vegetarian diet may also be a good choice. A recent meta-analysis of 11 vegetarian diet trials found significant lowering of total and LDL cholesterol levels, but not triglycerides.
A lacto-ovo vegetarian diet allows eggs and dairy, but excludes meat and fish. A 2018 study comparing low-calorie versions of this diet with the Mediterranean diet found that while both diets produced similar weight loss over a three-month period, the vegetarian diet lowered LDL-cholesterol to a greater degree and the Mediterranean diet reduced triglycerides levels more significantly. Olive oil, dietary fiber and many phytonutrients in the Mediterranean diet may be responsible. Weight loss with either diet may come not only from eating fewer calories, but also from eating more complex carbohydrates, legumes, fruits and vegetables, which are rich in fiber and more filling.
Either diet can help you achieve your goals. If you want to lose weight, reducing calories will be key. In general, a diet low in animal fats and refined carbohydrates and high in fiber, fresh fruits and vegetables promotes cardiovascular health. This can be achieved with either diet. With a vegetarian diet, it is important to ensure you eat adequate protein, avoid overloading on carbohydrates and keep a close eye on your vitamin levels. You might want to consider consulting a dietitian to make sure your diet is balanced. The bottom line: Choose a healthy diet that tastes good and you can stick with.
I am active and exercise regularly, but I am still overweight. My BMI is 32. I have read that being “fit but fat” is fine in terms of future heart risk. Why should I lose weight if I remain fit?
“Fit but fat” is sometimes referred to as metabolically healthy obesity (MHO), meaning overweight but lacking other cardiovascular (CV) risk factors. At any given point in time, the future CV risk in people with MHO appears similar to that of people of metabolically healthy normal weight. However, this may not be the case when observed over time. A recent analysis from the Multi-Ethnic Study of Atherosclerosis (MESA) reported that despite conferring a risk similar to normal weight at baseline, MHO did not reliably predict future risk. The reason is that in more than 12 years of follow-up, nearly one-half of individuals with MHO and no CV risk factors at baseline developed metabolic syndrome (MetS), which increased the risk of CVD 60 percent, compared with those with stable MHO or healthy normal weight. MetS is characterized by multiple factors, including obesity, high blood pressure, elevated blood sugar, elevated triglycerides and low HDL cholesterol.
Underestimating risk at a single point in time has implications for long-term follow-up. Preventing MetS, and treating it if it develops, is critical. The best way to prevent MetS is to prevent further weight gain, maintain regular physical activity/exercise and follow a diet that reduces saturated fats, refined sugars and carbohydrates.
If you are “fat but fit,” you should watch for and promptly treat high blood pressure, cholesterol abnormalities and rising blood sugar levels to help minimize your CV risk. Although cardiac fitness and the absence of metabolic abnormalities may be more important than weight alone for predicting what will happen over time, losing weight can help prevent MetS, has many other health benefits and is worth considering.