October 24, 2020
4 min read
Lichtenstein AH. Obesity & Lifestyle. Presented at: Cardiometabolic Health Congress; Oct. 21-24, 2020 (virtual meeting).
Lichtenstein reports no relevant financial disclosures.
Body weight, macronutrient distribution and sodium intake are all factors that need to be considered in the management of cardiometabolic risk factors and disease, a speaker reported.
Alice H. Lichtenstein
During a presentation at the virtual Cardiometabolic Health Congress, Alice H. Lichtenstein, DSc, Gershoff Professor of Nutrition Science, policy director and senior scientist in the cardiovascular laboratory at Tufts University in Boston, said adherence to guideline-based dietary patterns could improve cardiometabolic health and management of various risk factors.
“There is really no way of getting around it, body weight is going to impact blood pressure, fasting glucose levels, lipid levels and obviously abdominal obesity,” Lichtenstein said during the presentation. “But when we think about these different factors, the other thing we think about in terms of approaches to addressing them has to do with macronutrient distribution. It turns out that there are commonalities with fasting glucose levels, cholesterol, triglycerides and HDL cholesterol levels and one additional dietary factor, sodium. All of these together are ultimately associated with body weight and macronutrient distribution and we can think about body weight and macronutrient distribution together.”
According to the presentation, weight loss can be achieved in overweight and obese adults using targeted food groups rather than energy restriction.
Potential prescribed diets included:
- higher-protein with provision of food resulting in energy deficit;
- low-fat diet without prescribed energy restriction;
- lacto-ovo vegetarian-style diet with prescribed energy restriction;
- low-calorie diet with prescribed energy restriction;
- low-carbohydrate diet without prescribed energy restriction;
- low-fat vegan-style diet without prescribed energy restriction; and
- Mediterranean-style diet with prescribed energy restriction.
Lichtenstein also highlighted the PoundsLost trial, which evaluated the impact of macronutrient distribution on body weight and cardiometabolic risk factors.
Individuals were assigned to either higher or lower protein, fat or carbohydrate diets. Weight loss and levels of cardiometabolic risk factors were evaluated at 2 years.
Investigators found no significant change in weight loss among individuals assigned higher or lower levels of specific macronutrient intake.
Moreover, levels of various cardiometabolic risk factors including LDL, HDL, triglycerides and insulin concentration were also relatively unchanged between the two groups.
She also discussed the DIETFITS trial, published in JAMA in 2018, which compared percent energy from fat among participants who were assigned to either a healthy low-fat diet or a healthy low-carbohydrate diet.
Researchers observed that individuals in the healthy low-fat diet group had a drop in percent energy from fat from baseline to 1 year (34.8% to 28.7%), while those in the health low-carbohydrate group experienced an increase in percentage of energy from fat (36% to 44.6%).
“If you look at the total energy intake, it is remarkably the same, regardless of whether they’re on a high-fat or high-carbohydrate diet, which blows one of the things that we had assumed, that theoretically, if somebody was consuming a lower-fat diet with less energy density, they would automatically decrease energy intake,” Lichtenstein said in the presentation.
Weight change between the cohorts was nearly identical.
The similarities persisted even after stratification by insulin concentration at baseline.
“Regardless of whether they were in the lowest, middle or highest tertile of insulin concentrations, it just didn’t matter,” Lichtenstein said during the presentation. “What that is telling us is that the macronutrient composition of the diet is not what’s going to be the definitive factor as far as weight loss goes.”
Aside from body weight and macronutrient distribution, another major target dietary factor is management of dietary sodium, according to the presentation.
The 2013 American Heart Association guidelines for sodium intake recommended that individuals choose and prepare foods with little or no salt. The AHA recommended individuals limit sodium to less than 2,300 mg per day or to reduce sodium intake to less than 1,500 mg per day for additional BP lowering. However, if goals cannot be met, the AHA recommended individuals reduce sodium intake by 1,000 mg per day.
According to the presentation, some of the largest contributors to dietary sodium include breads, pizza, sandwiches, cold cuts, cured meats, soups and burritos or tacos.
“The challenge is that we really cannot accurately estimate sodium intake. The nutrient composition tables are not all that useful due to the reporting of the wide range of [contributing foods],” Lichtenstein said in her presentation. “It is really a guesstimate of what anyone is consuming. Unfortunately, for dietary sodium, there is no biomarker and that is because we regulate sodium concentrations and within a very narrow range. The only good way of assessing sodium intake is 24-hour excretion and now the feeling is you need multiple 24-hour excretion assessments, which is not going to be done in a clinical setting. Anything in terms of target numbers is going to be a guesstimate.”
She said recommendations from the 2015-2020 Dietary Guidelines for Americans; the AHA/American College of Cardiology; the National Lipid Association; the American Diabetes Association; and the American Cancer Society all agree that individuals should consume:
- a variety of fruits and vegetables;
- whole fruits and not juice;
- lean or low-fat meat;
- plant-based proteins and fish;
- whole grains instead of refined grains;
- non-fat and low-fat dairy (if dairy is consumed);
- nonhydrogenated oils from non-animal sources; and
- less sugar-sweetened beverages.
“The vast majority of sodium comes in from prepared food, not food cooked in the home. A lot of that has to do with dietary patterns, from processed food and not basic food items and food prepared at home,” Lichtenstein said during the presentation. “You can tell somebody to decrease sodium intake to 2,300 mg or less per day, but we know that it is virtually impossible for anyone to actually calculate that. Again, with dietary patterns, if we focus on those foods that are naturally low in sodium and products made from those foods where a lot of sodium is not added, we can have a real effect. It all comes down to dietary patterns and that is what we have to focus on.”