Teen Mom star Brittany DeJesus is engaged to boyfriend Steven, and sharing her happiness with the world. The proposal happened in beautiful Oahu, Hawaii, with DeJesus wearing a bright pink bathing suit. "He loves my birthday cake so much he wanna eat it foreva 💕," she captioned the post. How does she stay so fit? Read on to see 5 ways DeJesus 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!

DeJesus loves Japanese cuisine. "The traditional Japanese diet is considered one of the healthiest diets in the world," says Divya Jacob, Pharm.D. "The Japanese pride themselves in having one of the lowest rates of obesity in the world, as well as low incidences of certain hormone-dependent cancers. Usually, the Japanese eat three large meals and two snacks each day."

DeJesus enjoys fresh vegetables for lunch, especially asparagus. "Asparagus is a rich source of folate, a vitamin which is important for making red blood cells and for cell division – the synthetic version of this vitamin is folic acid," says registered nutritionist Nicola Shubrook. "Folate is an essential nutrient during pregnancy because it is needed for fetal development and protects against neural tube defects including spina bifida. Just 120g of asparagus (boiled) will provide your daily reference intake (RI) (200mcg). However, the NHS recommends that women planning a pregnancy or in the first trimester of pregnancy obtain 400mcg of folic acid a day."

DeJesus really does love her seafood—especially fish, fresh oysters, and shrimp. "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." 

DeJesus loves eggs, which many nutritionists consider a perfect source of nutrients. "Whole eggs are nutritionally rich, supplying almost every nutrient you need," says registered nutritionist Jo Lewin. "They are useful sources of some of the hard to get nutrients like vitamins D and B12 as well as the mineral iodine. Eggs are regarded as a 'complete' source of protein as they contain all nine essential amino acids, which we must obtain from our diet. Furthermore, if you choose brands enriched with omega-3 fatty acids, due to the diet the chickens are fed, you'll benefit from higher omega-3 fatty acids as well as fat soluble vitamins such as vitamins A and E."

DeJesus loves delicious, healthy kimchi. "There is growing evidence that fermented foods such as kimchi may improve levels of good bacteria in the gut, and may as a consequence improve symptoms such as constipation," Shubrook says. "Including a variety of fermented foods in the diet may improve intestinal health and as a result support the immune system and anti-inflammatory responses."