Beyond Calories – Nutrition Advice from Leading Researchers
Trying to figure out the best nutrition options as a person with diabetes can be a daunting task, and often there are mixed messages about what the best food options are.
At the 83rd ADA Scientific Sessions in San Diego, leading researchers helped shine a light on a few factors beyond calories that may help you make choices around food, including portion size, plant-based versus animal-based nutrition plans, and whether food is ultra-processed.
It’s no surprise that the researchers touched on portion size as a factor for discussing nutrition recommendations – eating more food contributes to greater calorie intake. However, Dr. Barbara Rolls from Penn State University presented research that added additional detail to this topic.
She discussed one study that looked at if there would be different results based on different methods for controlling portion size. Three groups either received standard advice (they were encouraged to “eat less” without much further guidance), portion selection (they were educated on which types of food to downsize and were provided with tools to guide portion selection), or pre-portioned foods (in order to structure their food environment and limit exposure to large portions).
The results of the study showed that all the groups lost some weight, around 10-12 pounds at the end of one year, but that the group using pre-portioned foods lost weight the fastest. Though this group also lost the most weight at six months, they tended to regain it back, leveling them out at around the same levels as the other groups. All three groups reported some challenges with sticking to their meal plans.
Rolls recommended a number of strategies for moderating the effects of large portions (which have become a staple in the average diets of many people), including:
Providing education and information about portion balance, such as food labels and guidance on how much of each type of food is ideal.
Modifying environmental signals, such as eating packaged meals that control portion size or providing to-go containers at the start of restaurant meals.
Reducing energy density, or how many calories per weight of a certain food. This could be increasing portions of fruits, vegetables, and other lower-energy foods so that you're eating more food (and feeling full) but intaking fewer calories.
Plant-based vs. animal-based foods
Dr. Christopher Gardner from Stanford University tried to answer the question of whether food type matters. Specifically, are plant-based foods any better than animal-based foods?
Both come with benefits and drawbacks. Animal-based foods include higher levels of important minerals and nutrients like iron, zinc, and calcium, but are also often higher in saturated fat and cholesterol. On the other hand, plant-based foods have higher levels of fiber, unsaturated fat, and antioxidants, but can also include added sugars and refined grains.
Gardner presented two studies, the first comparing alternative meat (plant-based protein) to animal meat and the second comparing ketogenic and Mediterranean diets. In the first study, plant-based protein contributed to a slight decrease in weight (around two pounds) and LDL cholesterol compared to animal meat.
In the second study, the ketogenic diet contributed to slightly higher LDL cholesterol values but resulted in greater weight loss and decreased triglyceride levels. Gardner remarked that although the ketogenic diet had slightly better results, overall, the most important factor affecting the results for both diets was the reduction or elimination of added sugars and refined grains – a characteristic of both the ketogenic and Mediterranean diets.
In fact, this was the major point of Gardner’s presentation. It’s not necessarily the type of food that matters most, but what other foods it is being eaten with, and what it may be replaced in a person’s diet. He ended his presentation by making a few recommendations like aiming to eat whole foods and plant-based options, plus minimizing added sugars and refined grains.
The last factor that was discussed and one that plays a larger role in conversations about nutrition is processed food.
Some experts stress that it may not just be about macronutrients (things like carbs, fat, and protein), but that we should be focused on limiting how much processed food people eat. In particular, we should be avoiding what is called “ultra-processed foods,” all of those convenient, tasty, and low-cost products like sodas, chips, cookies, cereal, and other packaged foods.
Dr. Kevin Hall from the National Institute of Health presented some of the research on this subject. Twenty adults were randomly given either unprocessed or ultra-processed diets for 14 days each (before switching to the opposite diet). The researchers made sure that participants were eating the same amount of macronutrients, salt, fat, sugar, and fiber, regardless of which diet they were on.
The results showed that:
Both groups self-reported the same average levels of hunger, fullness, and satisfaction.
The ultra-processed diets led to increased calorie intake, weight gain, and larger meal sizes.
Hall explained that it’s clear diets high in ultra-processed foods may negatively affect people’s health, but researchers are still not entirely sure what might be driving these effects. That's because, in theory, both diets were providing the same amount of macronutrients.
Future research would be helpful to understand what the underlying causes might be; Hall mentioned a new clinical study that they are recruiting for to try and measure just that.
Though all of these recommendations are important to think about, the impact that certain foods or nutrition plans have varies for each individual. In addition, the unfortunate reality is that accessing affordable, nutritious food is not always possible.
In the end, the best recommendation is to work with your healthcare team (including dietitians and nutritionists) to come up with goals and a plan that works for you. You don’t have to be perfect every meal, every day, because the best type of nutrition plan is one that is affordable, easy to follow, and fits within your current life – all while still keeping in mind the impact you want to have on your health.