Low‐carbohydrate and ketogenic diets
Losing muscle mass can prevent some people from dieting, but evidence suggests that a high-fat, very low-carbohydrate diet – also called a ketogenic diet – may help patients reduce weight and fat mass while preserving fat‐free mass, Dr. Hauser said.
The evidence regarding the usefulness of a low-carbohydrate (non-keto) diet is less clear because most studies compared it to a low-fat diet, and these two diets might lead to a similar extent of weight loss.
Rating the level of scientific evidence behind different diet options
Nutrition studies do no provide the same level of evidence as drug studies, said Dr. Hauser, because it is easier to conduct a randomized controlled trial of a drug versus placebo. Diets have many more variables, and it also takes much longer to observe most outcomes of a dietary change.
In addition, clinical trials of dietary interventions are typically short and focus on disease markers such as serum lipids and hemoglobin A1c levels. To obtain reliable information on the usefulness of a diet, researchers need to collect detailed health and lifestyle information from hundreds of thousands of people over several decades, which is not always feasible. “This is why meta-analyses of pooled dietary study data are more likely to yield dependable findings,” she noted.
Getting to know patients is essential to help them maintain diet modifications
When developing a diet plan for a patient, it is important to consider the sustainability of a dietary pattern. “The benefits of any healthy dietary change will only last as long as they can be maintained,” said Dr. Hauser. “Counseling someone on choosing an appropriate long-term dietary pattern requires getting to know them – taste preferences, food traditions, barriers, facilitators, food access, and time and cost restrictions.”
In an interview after the session, David Bittleman, MD, an internist at Veterans Affairs San Diego Health Care System, agreed that getting to know patients is essential for successfully advising them on diet.
“I always start developing a diet plan by trying to find out what [a patient’s] diet is like and what their goals are. I need to know what they are already doing in order to make suggestions about what they can do to make their diet healthier,” he said.
When asked about her approach to supporting patients in the long term, Dr. Hauser said that she recommends sequential, gradual changes. Dr. Hauser added that she suggests her patients prioritize implementing dietary changes that they are confident they can maintain.
Dr. Hauser and Dr. Bittleman report no relevant financial relationships.