Andrea Legarreta's daughter Mia Rubin is enjoying the sun and sea in Kanawa Island, Indonesia. Rubin posted a series of photos of herself wearing a pink swimsuit, standing next to a small boat in the surf. How does she stay so fit? Read on to see 5 ways Rubin stays in shape and the photos that prove they work—and to get beach-ready yourself, don't miss these essential 30 Best-Ever Celebrity Bathing Suit Photos!

Sushi is one of Rubin's all-time favorite cuisines. When ordering sushi, experts recommend sticking to the more traditional options. "As in many cases, simplicity is best," says Maxine Smith, RD, LD. "A simple roll is very low in calories. It could be equal to a light meal, so you're talking about 300 calories or so. You can easily double that when you get into some of the fancier roles and larger supreme rolls. Sushi can be a very healthy, green type of food — if ordered simply. If you have a craving for sushi, or if you enjoy that social aspect of eating sushi with other people, go for it. It can be a fun experience."

Rubin is a big fan of steak tacos. "Pick corn tortillas over flour tortillas," advises Kate Patton, MEd, RD, CSSD, LD. "Corn tortillas are more natural and less processed, making them a good source of fiber and magnesium (great for maintaining healthy muscles), not to mention they are significantly lower in calories, saturated fat, sodium and sugar compared to flour tortillas."

Rubin enjoys guacamole, a very healthy choice of snack. "Most of you know about the good heart-healthy fats in avocados," says Dr. Clara Barnett, ND, LAc. "Guacamole is a perennial favorite among Americans. But what about all those chips we tend to consume with it? Enter in Jicama, a tuberous root vegetable that is native to Mexico. It's crunchy, sweet and packed with a special fiber called inulin. Inulin can help slow the release of blood sugar and is an important prebiotic. It provides food for the good bacteria in your gut to thrive on. Viva la Mexico and viva the healthful and beautiful food of Mexico!"

Rubin eats lots of salmon, one of the healthiest options for protein. "We've long been told that fish is 'brain food', and there's convincing evidence to support this," says registered nutritionist Jo Lewin. "Studies suggest regular consumption reduces age-related brain loss and may improve memory – it's the omega-3 fatty acids that are responsible for this. Studies investigating the role fatty varieties of fish play have seen benefits for conditions like Alzheimer's disease, depression and multiple sclerosis."

Rubin enjoys spending time at the beach, and in the water. "The color blue has been found by an overwhelming amount of people to be associated with feelings of calm and peace," says Richard Shuster, PsyD. "Staring at the ocean actually changes our brain waves' frequency and puts us into a mild meditative state."