It’s not every day that you hear of people wanting to gain weight, particularly in today’s culture where thinness is revered. However, for those recovering from illness or struggling to beat their family genes, the prospect gaining a few healthy pounds can be frustrating.

It doesn’t have to be, according to Jennifer Sygo, a registered dietitian and sports nutritionist working at the Toronto offices of Cleveland Clinic Canada.

“I know there’s a certain segment of people out there who are laughing their heads off right now, saying you want to show me how to gain weight right before the holidays? But for those who really struggle with this, it can drive them crazy,” Sygo told Canada AM on Tuesday.

That list typically includes people recovering from cancer and active children who can’t put on muscle despite their best efforts. It also includes embarrassed individuals who have been teased all their lives for being too boney and unappealingly thin.

Sygo says the right way to begin this physical transformation is to make healthy foods the cornerstone of your program.

“We want people to gain weight in a healthful way,” said Sygo. “We don’t want to tell people to use junk food to do this.”

Choose dense, nutritious foods

Increasing one’s calorie consumption will nudge the scale upwards. However, this process should have little to do with the consumption of French fries, double-bacon burgers, gooey donuts and other nutritionally dead foods.

“Start by adding whole-wheat pastas and potatoes and make them a staple in your diet,” said Sygo. “The goal is to eat healthy, but energy-dense foods for weight gain.”

Drink more juice

Juices are commonly considered to be a taboo item among dieters, largely because of the extra calories that can easily rack up. However, those extra calories can be a boon to individuals who are eager to gain weight.

According to Sygo, the human brain registers juice consumption differently compared to chewing food. Unlike the consumption of solid foods, people can drink a lot of juice without feeling overly full. That feeling, plus the extra calories, will aid underweight adults and children.

“You can easily add 100 to 200 extra calories a day just be drinking fruit juices and smoothies,” said Sygo.

Simply add homemade smoothies and juices to regular mealtimes and you’ll see the scale inch upwards, she said.

Choose foods with nutritional punch

Eating foods rich in good fats is another key to gaining weight healthfully, according to Sygo. That list can include peanuts, walnuts, avocado and olive oil, which are all rich in heart-friendly monounsaturated fats. It can also include salmon, soy and sunflower oils, which are high in Omega 3 polyunsaturated fats.

“Start by using full-fat salad dressings on your salads, or olive oil when you are cooking,” said Sygo.

Adding high-calorie foods such as peanut butter and avocado to sandwiches will also boost weight-gain without compromising good nutrition.

Fool your brain with carbs

Finally, grabbing a few extra carbs throughout the day can stimulate the brain to eat more, according to Sygo.

“When you eat carbs, you feel hungry all over again in just a few hours,” she explained

Carbohydrate consumption causes a rise and fall in blood sugar levels -- and physiological event that can be utilized to trick the brain into eating more. However, Sygo cautions individuals once more to forgo bad carbs and choose healthy alternatives, such as whole grains and breads, and to pack on the pounds.