I would avoid trend diets like low-fat, low-carb like the plague. They are not sustainable and you deprive your body of much-needed nutrients.
Commit to eating CLEAN rather than eliminating a certain food group. Carbs are your body's primary energy source and many people find themselves miserable on a protein-only diet bc they don't have the "lift" that carbs provide.
Here are the things you should be steering clear of:
artificial colors / flavors
WHITES: flour, sugar
chemical / artificial sweeteners
preservatives (most are chemicals)
You see, when you eliminate things that are artificial, your body can recognize what you're eating as real food and it knows how to use it to function efficiently. When you're pumping your body full of chemicals, it short circuits its function, effecting your skin, weight, digestion, energy level, fertility, etc...everything!
When something is billed as "low fat", chemicals have been added to help it taste appealing to you. In the meantime, your hair, skin, nails and cell membranes are being robbed of what they need to thrive - fat!
Don't be "fat" or "carb-phobic".
In addition to avoiding most processed foods, try to supplement your diet with B vitamins, probiotics and enzymes. Enzymes help us to digest proteins and they greatly influence your digestion. Gross fact for the day: Most people have, on average, 15 POUNDS of waste in their system that they aren't passing. In addition to blocking the body's natural purifiers (elimination, etc) this is also contributing to excess weight.
I would avoid replacing everything with soy. The virtues of soy have been long touted over the dangers, but the truth is that unless the soy is fermented (as in the cases of natto and misso) it is NOT advisable to consume regularly. Soy contains phyto (plant) estrogens that mimic estrogen in your body. As you may know, an excess of estrogen is the cause of early puberty in children, and infertility, endometriosis, and breast cancer in women.
A baby being fed soy infant formula is ingesting the estrogen equivalent of 4 birth control pills a day!
All of that said, if you want to jump-start your weight loss I would advise the following:
1. Begin with a candida cleanse to rid your body of sugar, yeast and toxins. This will also stimulate your digestion.
2. Check out a market like Trader Joes, Whole Foods, or Wegmans to scope out more natural alternatives to the foods you already enjoy. This is a lifestyle change, not a diet, and is more sustainable.
3. Eliminate the additives listed above in all of their forms.
4. Exercise - even a walk each day will help to stimulate your metabolism and digestion
5. Give yourself at least 8 hours of sleep a night. Lack of sleep is tied to weight and overall health issues
6. Avoid unfermented soy
Good luck to you both!