PORTION SIZE AND CALORIC INTAKE
Culinary professionals have an unprecedented opportunity to help end the epidemics of obesity and related diseases. The restaurant industry now is starting to shift away from an older paradigm of big portions and low quality and has learned a vital lesson—measures that only reduce calories, without enhancing the quality of those calories, are destined to fail. The efforts to improve calorie quality are abundant, and now even major restaurant brands are experimenting with serving smaller portions of higher quality ingredients focusing on flavor.
The conventional approach to weight control is focused on calorie balance, with advice to “eat less, and move more.” Yet an astoundingly small proportion of people with excessive weight (more than two-thirds of the U.S. adult population) can maintain significant weight loss over the long term, despite the simplicity of this advice.
One explanation for this failure is a combination of low willpower and our “toxic environment.” Surrounded by inexpensive, high-calorie foods ubiquitously available in large portion sizes, many people are unable to exert self-control, so they mindlessly overeat and gain weight. Without doubt, the portions Americans eat have increased dramatically in the last half-century. For this reason, a major focus of public health in obesity prevention has been reducing and redefining portion size, as exemplified by the “100-calorie pack.”
However, a focus on calories alone disregards a fundamental scientific fact demonstrated repeatedly in the research laboratory: body weight is determined more by biology than willpower over the long term. When people cut back on calories, they will initially lose weight. But the body fights back, with rising hunger and slowing metabolism. This effect was illustrated in a recent and much-publicized follow-up of contestants on the show “The Biggest Loser.” Despite participants’ exceptional motivation (and the intensive support they received), virtually all described a constant struggle with their bodies and weight regain over time.
Certainly, genetic makeup helps to explain individual differences in predisposition to obesity. But our genes haven’t changed in recent decades, as obesity prevalence has skyrocketed. Beyond calorie abundance and more sedentary lifestyles, the quality of the food supply has changed, brought on largely by the excessive focus on reducing dietary fat.
During the low-fat craze of the last 40 years, the American public was told to eat all fats sparingly and instead fill up on carbohydrates. Responding to this call, the packaged foods industry marketed tens of thousands of reformulated food products that substituted fat with refined starches and added sugars. Unfortunately, these highly processed carbohydrates have exceptionally low satiety value (please see the box below) and adversely affect metabolism.
The 2015 Dietary Guidelines Advisory Committee found that fat in the diet, despite its high calorie content, does not uniquely lead to weight gain, but does increase satiety, and that some high-fat foods are highly protective of our health.
Increasing the portion size of refined starchy foods (e.g., most extruded breakfast cereals, white bread, white rice, fries) and added sugars (e.g., sugar-sweetened beverages, highly sweetened desserts) erodes diet quality and leads to obesity and chronic disease. Conversely, increasing the portion size and serving frequency of minimally processed carbohydrates (vegetables, fruits, legumes) and healthful fats (nuts, avocados, oil-based salad dressings) will displace less healthful foods, improve diet quality, and protect against chronic disease. In addition, high-quality plant-based proteins (nuts, legumes, soy products) and seafood have a special role in promoting satiety and balancing the metabolic effects of carbohydrates.
Over the past year, the restaurant industry has made progress mostly on calorie quality, through shifts to serve more plant-based foods and healthier animal-based protein choices like chicken. Efforts to actually reduce portion size along with improving quality remain in the “pilot” stage, with McDonalds, for instance, now in trials for a smaller hamburger made with fresh meat.
Operator attitudes may remain one of the biggest obstacles, as new research shows that while diners are interested in smaller servings of higher-quality protein, menu and purchasing decision-makers believe consumers still want larger servings. Of course, smaller portions won’t necessarily lead to higher prices even if food and ingredient quality also improves. But they may help address food costs. Successful pilots may be a harbinger of a change in operator attitudes and the mainstream adoption of smaller portions.
Flavor and aesthetic are two key tools that chefs can use to move diners toward healthier habits when it comes to righting portion size and balancing the right kind of calories. Chefs can hesitate to reduce portion sizes because customers often then complain that the value of the meal is not good (a perception of too little food for too much money). Ensuring that the healthier components on the plate are packed with flavor will help diners feel satiated, while clever plating practices can minimize perception issues around size.
Progress is being made on improving calorie quality. Efforts to also reduce serving size while serving higher-quality food have now entered the pilot phase.
- All calories are not alike. The belief that they are has produced misguided attempts to modify the food supply and led to confusion about what to do within the culinary profession and the foodservice industry. Simply lowering the total calories in a meal by reducing fat content will not produce benefit, if that meal is less satisfying and leads to subsequent overeating.
- To increase consumption of minimally processed carbohydrates, healthful fats, and high-quality proteins, changes in national policy that focus on decreasing prices of these foods relative to commodities are needed. Culinary strategies are also needed from the foodservice industry to make these options more available on menus and served in a variety of delicious ways.
- Progress is being made on improving calorie quality. Efforts to also reduce serving size while serving higher-quality food have now entered the pilot phase.
IN A WORD: SATIETY
According to the “energy balance” view of weight control, an eight-ounce sugary soda at 100 calories would be better for your weight than a one-ounce serving of nuts at almost 200 calories. Of course, common sense and definitive research say that’s not so. The sugary beverage might give you a quick rush of energy, but it will leave you hungry again and prone to overeating soon. In contrast, the nuts will elicit strong satiety—that long-lasting sense of fullness after eating. Even though fat has about twice the calories per gram of carbohydrate, high-fat foods typically produce greater satiety per calorie than processed carbohydrates. Some of the most calorie-dense foods in existence (e.g., nuts, olive oil, dark chocolate) are consistently associated with lower body weight than refined grains, potato products, and concentrated sugars. They are also demonstrably healthier for the heart. All calories are not alike to the body.
Often repeated phrases in the public health community and media such a s “balance energy intake with energy expenditure” and “there are no bad foods” do not reflect current science. These arguments distract us from focusing on the paramount importance of diet quality as a key determinant of long-term caloric intake and metabolic health for each of us individually— and ultimately as a key determinant of many of the largest food, health, and environmental challenges for all of us collectively.