For Lozoya, 17, not having a driver's license was part of the challenge. But the dearth of supermarkets in her South Los Angeles neighborhood choked with liquor stores, auto repair shops and warehouses made it even harder.
"I can't drive yet so I'm not gonna do anything extraordinary like jump on my bike and ride it for two or three miles and ride it back with tons of stuff on it, oh no," said Lozoya.
Seizing control of her kitchen, Lozoya helped her mom shed 50 pounds by banning lard from tamales and poaching chicken instead of frying it - and she is expanding her efforts to help her neighbors.
Lozoya is working to bring better food to one of the poorest communities in America, where neon lights illuminate a greasy fast-food vista and obesity and diabetes are rampant. While grocery stores and healthy restaurants are scarce, corner stores are stocked with beer, cigarettes, fried snacks and fatty sweets.
Lozoya's work with high school classmates to urge bodegas to stock healthier options is part of a larger campaign nationwide by nutritionists and community activists to eradicate so-called food deserts.
"Deserts are naturally occurring things," said Joanne Kim, chief operating officer of the Community Coalition of South Los Angeles. "We call this food apartheid because people have chosen to locate elsewhere even though there is substantial purchasing power here."
Between the three major Southern California grocery chains - Ralphs, Albertsons and Vons - there are six supermarkets in South Los Angeles, serving a population of about 688,000. By comparison, 19 supermarkets serve West Los Angeles' population of about 395,000.
Retailers blame theft in urban supermarkets, high employment turnover and lack of space for choosing to locate their stores elsewhere.
While farmers markets and trucks peddling fruits and vegetables have taken root in South Los Angeles, they are inconsistent and inadequate for the area's population, Kim said.
Some cities are trying to get more supermarkets into urban areas. The state of Pennsylvania invested $30 million five years ago and got 61 supermarkets opened in rural and urban areas.
The food disparity in South Los Angeles is an echo of the area's history, marked by decades of segregation and racial strife, dating back before the deadly 1965 Watts riots.
In the state's post-riot report, residents alleged price gouging and the sale of stale bread, rancid meat and rotten produce - complaints that re-emerged decades later after race riots erupted in the wake of the Rodney King verdict in 1992, said City Councilwoman Jan Perry.
South Los Angeles has shifted from a mostly black to a mostly Hispanic community in the last decade, with Latinos making up about two-thirds of the population, according to 2006 Census figures.
Today, fast food is king in South L.A. Nearly three-quarters of restaurants offer food on the go, compared to 42 percent in pricier neighboring West Los Angeles.
The city's Community Redevelopment Agency estimates the area could support 14 new grocery stores and 74 more restaurants. But few businesses are biting on incentives that include hiring tax credits, 35 percent electricity discounts for a year and low interest loans.
"You throw public subsidies at them, and they still don't come," Kim said.
Like many residents of Lozoya's community, where 28 percent of households live below the federal poverty line, she relies on the small corner grocery a few blocks from her home for chicken, fruit and vegetables.
Until recently, Los Compadres Market and Restaurant looked like most others. But Lozoya and her classmates gave it a healthy makeover through a grant from The California Endowment, a private health foundation that aims to create healthy communities.
Chips and candy were removed from the front aisle of the store; a large cooler in the back was stocked with fresh fruits and vegetables; fruits were carefully laid out to avoid bruising; milk and cheese chilled alongside beer.
"These problems are really killing our communities," said Marion Standish, a program director for the endowment. "They're really disabling young people all over the state and limiting their potential in very serious ways, and limiting all of our potential as a result."
It's those limitations that Lozoya is trying to push past - even in her own quiet ways at home.
A few times, she's convinced her parents to drive 45 minutes to Beverly Hills, where her father, a contractor who doesn't consider a meal complete without red meat, balks at the price of the perfectly ripe berries Lozoya piles into the cart.
"When we get to the checkout he says, 'This is the last time! Never again!'" Lozoya said, wagging her finger in imitation. "Now, me and my mom try to pay when he isn't looking."