いたってシンプル。

foods = modelname.objects.filter(カラム名=date.today)

.filter()がポイント

# views.py

from datetime import date
def foods(request):
# point!!!
 foods = Food.objects.filter(eaten_date=date.today())
 
 #合計キロカロリー
 kcal_list = [food['kcal'] for food in foods.values('kcal')]
 ttl_kcal = sum(kcal_list)
   # total_protein
 protein_list = [food['protein'] for food in foods.values('protein')]
 ttl_protein = sum(protein_list)
   #合計キロカロリー
 fat_list = [food['fat'] for food in foods.values('fat')]
 ttl_fat = sum(fat_list)
   #合計キロカロリー
 carb_list = [food['carb'] for food in foods.values('carb')]
 ttl_carb = sum(carb_list)
 
 context = {
   'foods': foods,
   'ttl_kcal': ttl_kcal,
   'ttl_protein': ttl_protein,
   'ttl_fat': ttl_fat,
   'ttl_carb': ttl_carb,
 }
 return render(request, 'base/foods.html', context)