If there’s one thing most Jews can agree on, it’s that fasting on Yom Kippur isn’t easy. Unless you happen to be an ascetic, or are really into the latest detox/cleansing trend, not eating for almost 25 hours can be challenging.

But there are ways to set yourself up for a successful fast, and according to Bay Area rabbis and dietitians, it’s all about how and what you consume heading into the Day of Atonement.

“According to Jewish law, we are supposed to have a heavy meal as our last one before fasting,” notes Rabbi David Booth of Congregation Kol Emeth in Palo Alto.

But is that a good thing?

Not according to clinical dietitian Denise Garbinski of San Francisco.

“You want to prepare your body the best you can, so you can be meditative and not focus on your hunger,” Garbinski says. “So, you want to eat a nutrient-dense meal, not necessarily a large meal.”

She recommends consuming complex carbohydrates such as sweet potatoes (rather than white potatoes), healthy fats (avocados, nuts) and high-quality proteins like tofu, seitan, beans or fish.

In other words, traditional Ashkenazi Jewish holiday fare — made with refined sugar and flour, high in fat and low on fiber — is not the way to go just before Kol Nidre.

“You want to feel full, not stuffed,” Garbinski notes. “You want to eat foods that break down slowly.”

While acknowledging recommendations for a balanced meal, Rabbi Judah Dardik of Beth Jacob Congregation in Oakland prefers to go the carb-loading route.

“Proteins need water to break down, and since we don’t drink water on Yom Kippur, I find that I do well if I go in to the fast having eaten mainly carbs,” he explains. “I’ll eat whole wheat toast, lentil soup and whole wheat pasta with a little cheese. I might also have a small portion of fruit, like melon.”

Aside from paying attention to what we eat, we also need to watch what we drink.

“Hydration is the key,” says Michelle Kuppich, a registered dietitian who is a Brandeis Hillel Day School mom and a member of The Kitchen, a minyan in San Francisco. “You will feel much worse on Yom Kippur if you have not been paying attention to how much you are drinking in the days leading up to the fast.”

According to Kuppich, an average healthy person should drink between 6 and 10 cups of fluid per day (81⁄2 cups per day would be right for someone who weighs 150 pounds). This doesn’t have to be water.

“Soups, broth, tea, fluid-replacement drinks, calorie-free beverages or beverages with nutrients such as calcium, vitamin D or protein such as milk or dairy alternatives are all options,” Kuppich says.

If you want to avoid debilitating caffeine withdrawal headaches, then you should start gradually cutting back on your coffee and caffeinated soft drink consumption in the week leading up to the fast. You’ll also be eliminating less as you reduce your caffeine intake, and this can help with overall hydration.

Avoiding alcoholic beverages is also a good idea, as they can lead to dehydration.

Rabbi Susan Leider of Congregation Kol Shofar in Tiburon points out that we do not recite Kiddush at the meal preceding the Yom Kippur fast. “It’s really interesting that during this joyous sendoff to depriving our body, we do not drink wine,” she says. “It seems the rabbis knew all about the dehydrating effects of alcohol.”

Chances are, even if you follow all these recommendations, you may still feel hungry as the day wears on.

“The key is not to go home,” warns Rabbi Andrew Straus of Temple Sinai in Oakland. “Go for a walk in the neighborhood around the synagogue, but don’t go home … You will be tempted to open the fridge.”

Dardik encourages congregants to participate in afternoon prayer services and discussion groups.

“Don’t think about fasting. Don’t psyche yourself out,” he says. “Work on keeping your mind busy and focused on Yom Kippur, which is a good thing.”

How we break the fast is also important. There’s a reason why many traditionally dine on bagels, cream cheese and lox after the final shofar blast is sounded.

“What you want to do after the fast is introduce small amounts of protein, complex carbs and healthy fat, and that is exactly what lox and cream cheese on a bagel do,” Garbinski says. “Go slow, and if you feel OK having eaten this, then you can have some alcohol and sweets.”

Straus is hip to that approach, but still, he prefers to honor his family’s age-old High Holy Days tradition. “We break the fast with a stiff scotch. Only after that do we eat.”